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4th International Meeting on Retouching of Cultural Heritage, RECH4 Host Venue | Academy of Arts, University of Split Title | POSTPRINTS RECH4 CROATIA Editorial Coordinators | Ana Bailão, Sandra Sustic Graphic Design | INEDITAR | Cristina Dordio Abstracts Proofreading | Graham McMaster Venue and Date | Split, Croatia, 2017 ISBN | 978-953-6617-42-5

The Organizing Committee would like to acknowledge the contribution of the the contribution of the members of the Advisory and Scientific Committees who made the selection of the communications and posters for the Meeting. We gratefully acknowledge the financial support and sponsorship of the Ministry of Science and Education of Croatia, the Ministry of Culture of the Republic of Croatia, the University of Split and the Split Student Centre. Special thanks goes to the Tourist board of Split, the City Museum of Split and the City of Split for their support in organising the social program of the Meeting. We express our gratitude to Split University Library and the Faculty of Chemical Engineering and Technology for enabling us with the conference venue. We

Organizing Commitees Support

would also like to thank the Split Department for Conservation for providing us with the workshop materials. Special thanks goes to RETES.HR print centre and OPG Mateo Curić. We also express our gratitude to Gabriela Rocha and FabLab Lisboa (Portugal) and to Escola Artística e Profissional Árvore (Porto, Portugal) for providing us with the conference badges.




ADVISORY COMMITTEE Visnja Bralic | Croatian Conservation Institute, Zagreb, Croatia Sagita Mirjam Sunara | Arts Academy of the University of Split, Croatia ORGANIZING COMMITTEE (alphabetical order) Ana Bailão | CIEBA/ University of Lisbon | Catholic Portuguese University/ CITAR, Portugal Ana Bidarra | Cinábrio, Conservação e Restauro | GeoBioTec Research Centre, Aveiro University, Portugal Francisco Silva | Árvore | Escola Artística e Profissional Árvore, Portugal Frederico Henriques | Catholic Portuguese University/ CITAR, Portugal LOCAL ORGANIZING COMMITTEE (alphabetical order) Jurica Matijevic | Arts Academy of the University of Split, Croatia Lana Kekez | Arts Academy of the University of Split, Croatia Sagita Mirjam Sunara | Arts Academy of the University of Split, Croatia Sandra Sústic | Arts Academy of the University of Split, Croatia Tina Tomsic | Arts Academy of the University of Split, Croatia TECHNICAL COMMITTEE Krešimir Bosnić | Arts Academy of the University of Split, Croatia Nikola Radošević | Arts Academy of the University of Split, Croatia Stjepan Krešić | Arts Academy of the University of Split, Croatia Bernarda Đurić | Arts Academy of the University of Split, Croatia Mateo Curić | Freelancer, Croatia Josip Pašalić | Arts Academy of the University of Split, Croatia Nikolina Drlje | Arts Academy of the University of Split, Croatia Silvija Matas | Arts Academy of the University of Split, Croatia Katarina Strinić | Arts Academy of the University of Split, Croatia Marija Curić | Arts Academy of the University of Split, Croatia Lucija Jolić | Arts Academy of the University of Split, Croatia 4


SCIENTIFIC COMMITTEE (alphabetical order) Ana Bailão | CIEBA/ University of Lisbon | Catholic Portuguese University/ CITAR, Portugal Ana Bidarra | Cinábrio, Conservação e Restauro | GeoBioTec Research Centre, Aveiro, Univ., Portugal


Ana Calvo | Complutense University, Madrid, Spain Agnès Le Gac | FCT - New University of Lisbon/LIBPhys-UNL, Portugal Ana Martins | Museum of Modern Art, MoMa, New York, USA Arianne Vanrell | Museo Nacional Centro Reina Sofía, Madrid, Spain Alicia Sanchez Ortiz | Complutense University, Madrid, Spain Alice Nogueira Alves | Fine Arts Faculty of the University of Lisbon/CIEBA, ARTIS, Portugal Antonino Cosentino | Cultural Heritage Science Open Source, Italy Barbka Gosar Hirci | Institute for the Protection of Cultural Heritage of Slovenia Branko Pavazza | Croatian Conservation Institute, Croatia Cristina Montagner | Centre of Physics, Campus de Gualtar, University of Minho, Braga, Portugal Emmanuelle Mercier | Institut Royal du Patrimoine Artistique, Bruxelles, Belgium Estelle De Groote | Institut Royal du Patrimoine Artistique, Bruxelles, Belgium Élia Roldão | Universidade NOVA de Lisboa, Caparica, Portugal Francesca Tonini | Ca´Foscari University in Venice | University of Urbino, Italy Fernando Costa | Polytechnic Institute of Tomar, Portugal Frederico Henriques | Catholic Portuguese University/ CITAR, Portugal Helena Melo | Évora University/HERCULES Lab/Évora University, Portugal Isabel Argerich | InstItuto del Patrimonio Cultural de España, Madrid, Spain Isabel Tissot | Archeofactu & LIBPhys-UNL, Portugal Ilaria Saccani | CESMAR7, Italy José Manuel de la Roja | Complutense University, Madrid, Spain Laura Fuster-López | Polytechnic University of Valencia, Spain Leonor Loureiro | Polytechnic Institute of Tomar, Portugal Lorraine Mailho | C2RMF, France Luís Pereira | Água de Cal - Conservação e Restauro, Portugal Lucija Močnik Ramovš | University of Ljubljana, Slovenia Mara Kolic Pustic | Croatian Conservation Institute, Croatia Ricardo Triães | Polytechnic Institute of Tomar, Portugal Rocío Bruquetas | Museo de América, Spain Rui Bordalo | Évora University/HERCULES Lab/Évora University, Portugal Rubén Morales | Complutense University, Madrid, Spain Silvia García Fernández-Villa | Complutense University, Madrid, Spain Sandra Sústic | Arts Academy of the University of Split, Croatia Stefano Scarpelli | Private conservation-restoration studio, Florence


Alba Guerrero

Kristina Krivec

Amparo Escolano Mena

Lana Kekez

Ana Bailão

Leonardo Severini

Ana Bidarra

Leonor Loureiro

Ana Carolina Rodrigues Ferreira

Liliana Querido Cardeira

Ana Oblak

Maja Sučević Miklin

Anita Klančar Kavčič

Mara Kolić Pustić

Antonija Gluhan

Marisol Valenzuela

Bakonyi Tímea

Martina Bagatin

Beatriz Doménech García

Martina Lesar Kikelj

Eve Bouyer

Martina Vuga

Branko Pavazza

Mladen culic

Brian Baade

Paolo Roma

Clara M. Prieto

Pedro Antunes

Dorotea Krstić

Rosa Senserrich-Espuñes

Nancy von Breska Ficovic

Ruben Morales

Emmanuelle Mercier

Sagita Mirjam Sunara

Erika Rabelo

Sandra Šustić

Filip Adrian Petcu

Sanela Huzjak

Francesca Tonini

Sara Aničić Eterović

Frederico Henriques

Serena Francone

Gabor Erdei

Simona Pannuzi

Ivana Letilović

Simona Škorja

Julija Baćak

Stefano Scarpelli

Jure Matijević

Tina Tomšić

Katarina Alamat Kusijanovic

Vanessa Ubaldi

Katarina Tomaš

Visnja Bralic

Kristin deGhetaldi 7


The retouching process is one of the last steps of a conservation and restoration intervention. Expectations are normally high and conservators are continuously challenged to acquire innovative techniques and new materials to satisfy this need. One important part of retouching is to use and incorporate materials with long-term durability, but always based on the concept of minimal intervention. The accomplishment of these expectations entails a detailed diagnosis and planning of the treatment with attention to function, to aesthetics and to the stability of the materials. Communication is the key word for a good intervention. Proper communication will not only enhance the conservator– owner relationship but also provide greater acceptance of the treatment planning. The evolution of digital technology has created exciting opportunities for improving this communication process and to facilitate a smooth workflow, from diagnosis to the final treatment and maintenance phase. The International Meetings on Retouching of Cultural Heritage (RECH), initiated in 2013, have gained an international audience, bringing together conservation-restoration professionals, academic members, students and independent researchers from across the world. The conferences aim to promote the exchange of ideas, concepts, terminology, methods, techniques and materials applied during the retouching process in different areas of conservation. This postprints presents the articles of the fourth edition of RECH that took place in Split (Croatia) from October 20th to October 21st, 2017 and was jointly organised by members of the Escola Artística e Profissional Árvore, the Faculty of Fine Arts of the University of Lisbon, the Arts Academy of the University in Split, the Catholic University of Portugal, the Cinábrio and University of Aveiro.The Scientific Committee, consisting of renowned experts



in the conservation-restoration field, selected 24 abstracts for communications and 16 abstracts for poster sessions, not all publish here. The titles cover a wide range of topics - from digital options for documentation, diagnosis and


treatment, to new solutions and materials for filling and retouching of losses. The organizers give their thanks to all the members of the RECH Committees for their diligent work in setting up the programme and to the sponsors for their generous support.

Ana Bailão on behalf of the Organizing Committee Sandra Šustić on behalf of the Local Organizing Committee





22 An opportunity to reflect on differentiated retouching techniques used in Italy: methods and materials. Problem solving in a private practice context. Leonardo Severini

28 The bad reputation of neutral retouching Eve Bouyer

38 Baroque Master Mattia Preti and his workshop: two series of four evangelists from Dubrovnik Maja Kolić Pustić, Carlo Galliano Lalli, Nancy von Breska Ficović

46 “All Saints are in the detail“: Retouching of a painting by Girolamo da Santa Croce Katarina Alamat Kusjanović; Sandra Šustić

56 The suitability of powdered micro-cellulose for its use in paper conservation Rita Udina, Amparo Escolano

66 The use of Aquazol® 500 as a binder for retouching colours: analytical investigations and experiments Vanessa Ubaldi, Roberto Bestetti, Roberto Franchi, Emanuela Grifoni, Pier Paolo Lottici, Francesca Modugno, Richard Wolbers, Daphne De Luca

80 PVAC Retouching Colors: a brief history and introduction to Goldens’s newly formulated PVA. Conservation Colors Kristin deGhetaldi, Brian Baade, Joyce Hill Stoner, Jim Hayes, Samantha Alderson

88 Using watercolour markers in chromatic reintegration Liliana Cardeira, Ana Bailão, João Linhares, Sérgio Nascimento

98 Filling and colour reintegration in a single step Martina Vuga

106 Retouching methods on the albumen and coloddion photographic processes from the Croatian State Archives Martina Bagatin

112 Dealing with unsuitable retouches: the steps toward successful reintegration Ana Oblak

120 Use of coloured synthetic fillers: the case of St Nicolas, a Baroque painting by Fortunat Bergant Simona Škorja


130 Mapping lacunae for chromatic reintegration with computer graphics software Frederico Henriques, Ana Bailão, Rui Bordalo, Agnés Le Gac, Alexandre Gonçalves, Liliana Cardeira, Eduarda Vieira, António Candeias


138 Gold and polychromy on stone: a proposal of retouching methodology that can apply on all tridimensional artworks Simona Pannuzi, Marisol Valenzuela, Daria Montemaggiori, Giorgia Galanti

144 “The golden stain of time”: the inpainting of gildings on wooden sculpture Emmanuelle Mercier, Erika Benati Rabelo

152 A case study on reconstruction of the faux marble paint layer on a baroque wooden tabernacle Maja S. Miklin

160 Retouching approaches to artwork on paper in the laboratory for conservation and restoration at the Croatian State Archives. Retouching of a Watercolour Landscape and a Map of Zadar from the 19th Century Sanela Huzjak

166 Approaches to the conservation treatment and chromatic reintegration on watercolours, charcoal drawings, and a lampshade handpainting Leonor Loureiro

176 The photographic retouching as fundamental intervention Rubén Morales González





188 Influence of lighting sources in the processes of colour reintegration Beatriz Doménech, Vicente Guerola Blay, María Castell Agustí

194 Chromatic reintegration in late 19th century albumen prints: analysing and testing different methodologies in Calouste Gulbenkian´s albums Alba Guerrero

200 Selective removal of layers in layered systems of retouching: research project in progress Sagita Mirjam Sunara, Dorotea Krstić

206 Reconstructing of The Sappho painting towards a better understanding in retouching Marija Lena Bosković, Sandra Šustić

212 The issue of metamerism in Mario Agrifoglio’s paintings. Identification of fluorescent pigments through raman spectroscopy to define a methodology for retouching Serena Francone, Silvia Bruni, Chiara Zaffino, Katia Galli, Vittoria Guglielmi, Maddalena Boscacci

218 Retouching religious paintings – examples from private practice Lana Kekez, Kristina Krivec, Julija Baćak

226 Calcium hydroxide nanoparticles for wall painting retouching. The chapel of Saint Michael in the Royal Monastery of Pedralbes, Barcelona Rosa Senserrich-Espuñes, Lidia Font-Pagès

232 Retouching a double-sided 19th century processional flag-icon Filip Adrian Petcu

244 Selecting methods for retouching a polychrome and gilded altarpiece with elements dating from different periods Sara Aničić Eterović, Ivana Letilović, Katarina Tomaš

248 Mixing and matching. A survey of retouching materials Ana Bailão, Liliana Cardeira

256 Fernando Mardel, a portuguese painter-restorer. Retrospective of his retouching work Carolina Rodrigues Ferreira, Fernando António Baptista Pereira, António Candeias, Mercês Lorena


264 The reconstruction of three strongly damaged panel paintings of a 16th century Sienese predella Ágnes Kuna, Tímea Bakonyi, Erdei Gábor

270 Inpainting in Exhibition Clara M.Prieto





Nome artigo


Keywords chromatic compensation of paint losses; Differenciated retouching; Hatching treatments;


Inpainting; close inspection, in such a way that it

Retouching techniques;

neither competes with the original nor

Selezione Cromatica;

conceals the traces of time.

Visible retouching.

The goal of these methods was to obtain an objective, rational and scientifically based inpainting tool


limiting the subjectivity of restorers [2]. The crucial subject of retouching and chromatic compensation of paint losses has, over the centuries, received a great number of solutions, materials and techniques. Restorers are called to intervene on the face of paintings with the risk of altering the original aspect of the artwork.


The extents, limits and methods of loss reintegration have been the

Leonardo Severini

subject of international debates and attempts were made to impose

E-mail address: leonardoseverini@gmail.com

regulations. In general conservators are in agreement on the reversibility


of the materials to be used and the

The techniques of differentiated

limitation of retouching only inside

intervention on paint losses in Italy are

the losses, but currently there are

two: Roman tratteggio and Florentine

various methods to do that.

selezione cromatica.

The Italian position in this matter

The reason why there are two

was to propose an unusual choice of



re-integration using the differentiated

there are two Italian public Institutes

techniques, reflecting a specific rationale

of conservation of paintings: ISCR

of systems in order to give as much

in Rome (Istituto Superiore per

visibility as possible of the autograph

la Conservazione ed il Restauro;

parts of a painting with no later additions.


They were originally conceived to

Florence (Opificio delle Pietre Dure;

avoid the risk of falsification caused by

founded in 1975). [3][4]







deceptive or cosmetic retouching, not

These two institutes belong to

considered a valid response to the aim

the Ministry for Cultural Heritage

of making original text distinguishable. A

(MIBACT: Ministero dei Beni e delle

position derived from Cesare Brandi’s

Attività Culturali e del Turismo) and

Italy has made a specific choice in pictorial treatment of lacunas: Roman Vertical

a cycle of seven large panels painted by

tratteggio and Florentine selezione cromatica. Both methods are based on the same

Giuseppe Valeriano and Scipione Pulzone

approach avoiding deceptive retouching in favor of visible techniques to make

for the Chiesa del Gesù in Rome at the

thinking who refused the notion

they considerably affect the choices

losses recognizable at a close range of view. Currently in Italy we continue to carry

end of XVI century.

of reconstructing the areas of loss

of the officials who supervise the

out recognizable retouching on public paintings. Nowadays, however, the choice of

Removing opaque coatings, old retouching

“by analogy” which he considered a

conservation of public works. [5][6]

intervention is made mostly by art historians who are responsible for and in charge

and overlaid fills, the Superintendence

of public conservation projects, so restorers run the risk of taking a secondary

decided for a visible intervention in a

falsification of history and an aesthetic

role in the decision making concerning


large amount of losses. We therefore

of the lack of a unified approach in Italy, but also because of the significant costs

decided to apply method of selezione

that differentiated intervention could represent, a private conservator working on


public paintings has to find compromises in terms of time and costs, when resolving

in varnish colors onto a flat chromatic

problems. The case presented in this paper concerns the retouching treatment of

tempera base laid on the fillings.

the presentations of artworks.





offense. Visible retouching aims at reintegrating the image by reducing the visual impact

The diffusion of the two methods is linked to the areas of influence of the two National Institutes along the Italian territory



of the losses while ensuring that the

In any case these two methods evolved

restoration is clearly recognizable upon

over time with experimentations and

panels in-wall shrines are jealously conserved. The need for intervention was due to the structural problems of stability of Figure 1 • Walk-in of the Chapel of Madonna della Strada after treatment.

supports. To obtain a correct intervention on

adapted to specific

government ministry officials (most of

to that adopted by Italian Divisionist

the wooden panels and consolidation of

cases. Nevertheless the differentiated

whom are art historians) that should

or Neo-Impressionist painters who

paint layers we had to remove opaque

techniques are presented and taught

verify the quality and rightness of the

tried to obtain an effect of maximum

coatings, old retouching and overlaid fills.

(frankly not always properly) by

interventions but also often decide

luminosity and brightness by taking

Once the wooden supports were

both the national schools (ISCR and

which methods have to be used.

advantage of the additive color mix

stabilized, the situation after the


conclusion of the cleaning operation



OPD) as practically the only solution

It’s a matter of fact that only in few

to lacunae reintegration, without

cases do directors of conservation

The case presented in this paper is



treatments decide to choose the

the retouching treatment of a cycle of

using the mimetic method, which is

option of visible retouching, that is used

large panels using selezione cromatica

considered as falsifying in the context

less and less often, because it takes


of public education.

longer and therefore costs much

treatment, that took more than three

It must be considered however that

more and is not always well executed.

years to complete, was on seven large

restorers with their own private studios

So it’s important to know the

paintings (2,50 meters height each)

Superintendence of Rome, an art

work both for public institutions and

procedures perfectly in order to do a

by Giuseppe Valeriano and Scipione

historian, in charge of the intervention

private collectors, who never ask for a

satisfactory job.

Pulzone at the end of the XVI century

decided in favor of differentiated way

Both methods are technically built

for the Cappella della Madonna della

of inpainting following the principle of

up by juxtaposition of fine brush

Strada inside the Chiesa del Gesù, the


, meaning that they

strokes of pure transparent color

mother church of Jesuits in Rome.

Therefore I decided to apply

used differentiated inpainting for

(usually watercolor) applied with an

The cycle represents one of the most

the method of selezione cromatica

most public paintings and mimetic

hatching technique.

important example of pictures from

not traditionally carried out with

the Counter-Reformation.

watercolors on white fills ground



differentiated treatment! “Conservators became bilingual so to speak”


treatment for everything else.

Their differences mainly consist in




revealed on the painted side many extensive areas of losses. The question was which kind of retouching method should we adopt in this case? The




Therefore the overview of the

the direction of brushstrokes: vertical

The artists were called to decorate

but through hatching treatment in

situation in Italy is slightly complicated

for the tratteggio and following forms

an entire chapel with Stories of the

varnish colors (Gamblin Conservation

as you can find different retouching

and pictorial ductus in selezione

Virgin and they chose to use the oil on

colors) onto a flat and even chromatic

wood technique especially because

base tempera gouache (Schmincke

When looking at the painting in

the panels, fitted with hinges, had

gouache colors) laid on the fillings. [12]

It depends on a lot of factors;

the normal way, hatched colors

to cover the greatly valued treasure

The use of a chromatic base is

generally decisions are taken by

melt together producing a sense of

of the church: the relics. In fact at

a practical expedient that greatly

public conservation institutions and

wholeness. The technique is similar

the back side of each of the seven

reduces the time needed to carry out

solutions within the same museum, collection or church.


Figure 2 • Orthophotography of the Chapel of Madonna della Strada after treatment.

Leonardo Severini



Figure 3 • the paintings after cleaning with losses already filled with gesso and rabbit skin glue.

the job, and the amount of varnishcolor retouching needed. At the same time it preserves the infilled surface, by creating a protective “skin”, which is morphologically similar to the surface of oil paint and therefore reduces the porosity of the gesso fillings.

Figure 4 and 4bis • details with chromatic bases (left) and after hatching treatments with varnish colors (right).

The filling was texurized with liquid putty.Texturing of the fills is important to obtain the optimal visual integration of the treated area, especially for varnished objects. The definite matching of the color has been carried out with strokes of three-toned varnish color after a first

Figure 5 • detail with filled lacunas (left) and after hatching treatment (right).

protective coating of varnish. To obtain a vibrant effect it is important that the brush is loaded in such a way as to produce a dense, sharp, distinct stroke of color that is not rigid (as in

An opportunity to reflect on differenciated retouching techniques used in italy: methods and materials. Problem solving in a private practice context.


tratteggio) but short and fractionally

also useful for any kind of retouching

curved. Here it is important to select

techniques. By choosing pure colours,

of paintbrush, solvents and quality of

primary and secondary, splitting the

Scientific article:

palette and materials used carefully.

tonality using subtractive synthesis we

[1] LACUNA, Atti dei convegni 2002/3 al

can match the colour in order to get

Salone del Restauro di Ferrara. Edifir editore,


the best result in terms of saturation, brightness, depth and vibrancy of the

This kind of hatching reintegration,

inpainting in a reasonable time and

if not done well and subtly, can be

corresponding to the budget planned.

perceived as an evident foreign


1963. [4] Baldini U., Teoria del Restauro e Unità di Metodologia, Nardini ed. Firenze 1988. [5] Bonsanti G., Theory, methodology, and

[6] Reifsnyder J.M., Cesare Brandi and






Italian conservation theory: In and out of




context. In Postprints: American Institute for

INPAINTING The Painting Speciality Group

Conservation – Paintings Speciality Group

of the American Institute for Conservation

16:23-32. 2003.

of Historic and Artistic Works (AIC), C. A.

practical applications – painting conservation

[7] Olsson N., From mimetic to differentiated:

in Italy in the twentieth century. In: EARLY

traditions and current practices in Italian

of paint loss: theory and practice in the



inpainting. In Postprints: American Institute for

[9] Ramsay L., An introduction to visible Italian

conservation of easel paintings. In IIC Reviews

Conservation. Proceeding of a Symposium at

Conservation (AIC) - Speciality Group 16

retouching techniques. Postprints of the Image

the Yale University Art Gallery (April 2002)

(2003) 23-32.

Re-integration Conference. 15-17 sept. 2003

Firenze 2004. [2] Muir K., Approaches to the reintegration

in Conservation n°10 2009.

element. [13]



edited by P. Sherwin Garland, YUAG 2003.

[8] Betts P., Italian differentiated inpainting

Metzger (ed.), C. Maines (ed.), J. Dunn (ed.), 2011.

Northumbria University. Newcastle upon Tyne, UK. Northumbria University press. 2007

Although the Italian differentiated

Figure 8 • the seven panels after treatment

method appears to be very complex and is rarely

[3] Brandi C., Teoria del Restauro, Rome

[10] Ciatti M., Approaches to retouching and restoration: pictorial restoration in Italy, in Early

requested, It is

Italian Paintings: approaches to conservation.

important nevertheless to know the

Proceeding of a Symposium at the Yale

correct application methods not only

University Art Gallery (April 2002) edited by

to respect the principle of visibility

P. Sherwin Garland, YUAG 2003.

and recognisability of retouches from

[11] Leone G., (a cura di) Le storie della Ver-

original parts but also to acquire a

gine nella Cappella della Madonna della Strada al Gesù - Il restauro. Gangemi editore 2017.

different perception of integration

[12] Christensen C., and



CONSERVATION Figure 6 • detail of selezione cromatica with distinct few brushstrokes of pure color to match tonality

Figure 7 • detail of selezione cromatica with distinct few brushstrokes of pure color to match tonality

Inpainting binders In




INPAINTING The Painting Speciality Group of the American Institute for Conservation of Historic and Artistic Works (AIC), C. A. Metzger (ed.), C. Maines (ed.), J. Dunn (ed.), 2011. [13] Severini L., et al. An unusual case of integration and its solution, in: MIXING AND MATCHING Approaches to Retouching Paintings. Archetype Publications in association with ICON, BAPCR. 2010. Website: [14] www.leonardoseverini.it


Leonardo Severini

An opportunity to reflect on differenciated retouching techniques used in italy: methods and materials. Problem solving in a private practice context.


Keywords Neutral; Visible restoration; Aesthetics;


Ethics; Other restorers such as Filippo Fiscali


completely aligned with Cavalcaselle’s recommendations. Fiscali is responsible for an interesting example of neutral integration made around 1890 on Benozzo Gozzoli’s frescoes at San


Eve Bouyer

Francesco Church in Montefalco

Centre de Recherches en Archéologie et Patrimoine, Université libre de Bruxelles; CP 133/01, Avenue F.D. Roosevelt, 50, B-1050 Brussels; Eve. Bouyer@ulb.ac.be

textual reference to neutral retouching

In The Death of the Knight of Celano,

on any multicolour object: paintings,

to the Italian art historian Giovanni

an extensive lacuna was filled with a

polychrome sculptures, decorated

Battista Cavalcaselle (1819-1897)



single brown colour matching the

who stated that restorations should

predominant colour of the scene but in

be recognisable to the naked eye in

a duller version (a colour photograph

order for scholars not to be deceived.

can be seen on the Wikiart website [5]).

A neutral restoration can be done

ceramics, posters, etc. The





understood in different – even contradictory – ways, as

will be

Boito written in the form of a dialogue:

without reconstructing them.

della Francesca’s frescoes depicting

“Veda, per i quadri e per i dipinti a

the legend of the true cross, in the

buon fresco un ordine circolare del


San Francesco Church in Arezzo

[3; 4]


Ministero impone che le lacune ed i


Once he had attained a ministerial

buchi si riempiano di tinta neutra tutta


post, Cavalcaselle imposed neutral

uguale, sicché il riguardante non possa

toning throughout the recently united

venire menato per il naso dall’abile

Italian Kingdom via a circular published

restauratore” [6].

Although the term “neutral” was most likely used first in the field of painting restoration,

were realised earlier in other fields.

to be cautious when using it. For ethically conscious conservators, it is important to overcome the lack of popularity of neutral retouching and to give it the attention it deserves.


1861 by Gaetano Bianchi, on Piero

This approach, since its first use in the 19th century, has always had proponents

The terminological validity of the word is problematic in itself: conservators need


the famous 1893 essay by Camillo

This paper reviews the notion of neutral retouching in conservation.

The meaning ascribed to the term “neutral” can differ from one author to another.


on a painting was made in 1858-

the inconvenience caused by lacunas

from a bad reputation.


mentioned in Conservare o restaurare?,

Broadly, “neutralising” means reducing

and detractors. Today, the distrust of the notion is such that we could say it suffers

Directly influenced by Cavalcaselle’s ideas, the first neutral integration

shown in the third part of this paper.






A red-figured vase restored around 1830-40 is evidence of this: it still has a lacuna filled with a flat uniform colour matching




colour [1]. Marco Ciatti attributes the first explicit

30 January 1877, which states lacunas

(You see, for panels and frescoes,

were to be filled with a colour

a ministerial circular requires that

matching but less intense than the

lacunae and holes are filled with

surrounding colour(s)

uniform neutral tint, so the viewer


[2; 4]

Neutral toning quickly became the subject of controversy and some

cannot be led by the nose by the skilled restorer).

restorers, such as Cosimo Conti,

The lines following this quote

clearly expressed their disagreement

indicate the existence of an early

with the ministerial guidelines

debate about neutral restoration. One



protagonist in Boito’s dialogue claims

Even if quite popular, neutral toning

the original ones. Influenced by the

that it disrupts aesthetic pleasure, and

coexisted with more reconstructive

Gestalt theory of visual perception,


is unjustified where completion is non-



he believed that such colours do not

flourished over a few decades of the

conjectural. The other responds that,

criticised: German publications in 1928

blend in, but on the contrary impose

to him, having doubts concerning the

reflected a profound debate between


painting’s authenticity is much more disruptive


[6; 7]

Another early critique of neutral retouching was formulated in 1903




suggests that neutrality is a myth in

in 2017 by Rita Udina, a book and


paper conservator from Spain. She reached

wrote that it can be a “good solution”

20th century. Brandi can be seen as

a paroxysm in a book by Knut

and provided a link to her personal


a starting point for a reaction against

Nicolaus published at the end of the

weblog showing an example of

proponents and detractors of neutral

lacunas into figures that interfere with

this purism. The famous painting

1990s in several languages. Nicolaus

neutral retouching on a poster, with


the painting’s legibility.

conservator Helmut Ruhemann is

associates neutral toning with a form

a flat uniform blue colour closely

He prescribed the use of colours

a prime example of this change in

of dogmatism, which is a severe

matching the one surrounding the

that force the lacunas to look like they

attitude. Initially, he promoted neutral

accusation. And even more extreme, he

large lacuna [19] (figure 1).





. The same publications


show that neutral restoration was often executed using grey








by the architect Giuseppe Sacconi,

Cesare Brandi reacted to the success

are on another level than the painting:

retouching: in a 1931 paper, he

states that he observed its use mainly

Sheila Landi, a textile conservator

who was in charge of the restoration

of neutral retouching by promoting a

in the foreground or – preferably

explained that in order to “neutralise”

among conservators who struggle with

in the UK, strongly reacted to the

work in the upper Basilica of Assisi.

new compromise – the tratteggio. For

– in the background

. One could

the effect of paint losses, he used

mimetic or normal retouching [17].

LinkedIn post, writing, “There is

Commenting on Giotto’s St Francis

the sake of the artwork’s “potential

consider this as some kind of neutral

flat colours similar to either those

mourned by St Clare, he wrote that

unity”, he advocated for a more

restoration, since it was intended to

surrounding the lacunas or the


concerned trying to dye a ‘neutral

the choice of a single neutral colour

reconstructive but still recognisable

reduce the inconvenience caused

brownish underpainting


colour’ it always ends up too green,

for a painting can be wrong: “In many

approach. However, he


by non-reconstructible lacunas (in

1968, he declared himself against “too

areas, it will appear dark against light,

that “where conjecture begins” (to

the broad sense mentioned at the

visible” retouchings, acknowledging

and vice versa…and will be more

quote Article 9 of the 1964 Venice

beginning of this paper).


disturbing to the eye than a simple

Charter), the lacunas were not to be

Similarly, Laura and Paolo Mora and

loss of paint from the intonaco” [4].

reconstructed, even with recognisable

Paul Philippot considered some losses

Conservators used to worry mainly

well illustrated by a short LinkedIn

A first observation is that “neutral”

Neutral retouching had a lot of

retouching techniques. For these non-

non-reconstructible and wrote that

about the material authenticity of

discussion entitled “The Diplomatic

might not be as “diplomatic” as the title

success in Germany in the 1920s and

reconstructible losses, he proposed

“neutral tint” is “a totally inadequate

artworks, in reaction to past excesses

Neutral Colour”

of Udina’s post suggests. Secondly, Landi

in Europe in the mid-20th century

[8; 9]


some kind of neutral restoration.

term and a wrong notion, the misuse

of deceptive and unethical restoration.

This can be linked to a purist tendency

Connoisseurs of Brandi’s work might

of which is usually nothing more than

But with the consolidation of ethical

called “archaeological” or “analytical

– rightly – disagree that he did so,

an excuse for avoiding the critical

guidelines in conservation practice

restoration” that strongly rejected

as he famously criticised the idea of

problem”. They recommended filling

(reversibility and no overpainting of

illusionism . Artworks were perceived

neutral colour.

these losses in with the natural texture

the original), attention to aesthetics

and colour of the arriccio [12].

regained its original importance.



Neutral toning embodies a purist




. But in





merely as historical documents, and

On one hand, Brandi highlighted

their aesthetic value was put aside.

a terminological nonsense: neutral

In the same vein, Umberto Baldini

This helps explaining why neutral

In the name of authenticity, later

colours do not really exist, because

considered that some lacunas are

retouching increasingly earned a bad

additions were systematically removed

any colour will always alter the



reputation. This is made obvious by

and all losses were treated with a

perception of the artwork. On the

not. For the former, he devised the

the fact that today the term “neutral”

minimal, “archaeological” approach,

other hand, he disagreed with how

selezione cromatica and for the latter, a

is frequently used within quotation

where neutral integrations were the

those around him executed neutral

new and very elaborate form of neutral

marks and/or preceded by the

logical choice.

retouching: with colours resembling

retouching: the astrazione cromatica

locution “so-called” [3; 9; 16]. This clearly

Eve Bouyer





no such thing. As far as textiles are

too pink or too yellow. If used as a Meanings ascribed to the term

background for other colours all the

“neutral” can be contradictory and

so called neutral colour does is kill the

lead to misunderstandings. This is

object stone dead.”

. It was launched


Figure 1 • P  aper poster, «In the name of peace and progress!», Valentin Viktorov, 1959 © Rita Udina (http://ritaudina.com/

The bad reputation of neutral retouching


Figure 2 • Bowl with the Martyrdom of St Lorenzo, majolica from Urbino by the Painter of the basin of Apollo, ca 1521–1532; International Museum of Ceramics in Faenza, ac. n° 4974 (A. Orombelli donation, 1952) © Faenza, Museo Internazionale delle Ceramiche

surrounding colour.

clay body etc.) or of another layer

It was mentioned




ceramic’s white glaze etc.). This


option was mentioned by Paolo and


Laura Mora and Paul Phillipot



and by Helmut Ruhemann [14]. It is


sometimes called “natural neutral” [8]


different understanding of the term “neutral”. Indeed: a neutral colour might mean either matching a colour that appears on the original or choosing one extraneous to the original. The





Conservation of Paintings proves that this terminological ambiguity is not new. The adjective “neutral” was indeed used twice in the book: first, it mentioned a “neutral tint that matches the surrounding colour”, then referred to “neutral grey”



When matching (more or less closely) a colour that appears on the original, there are at least three options. First, matching the main colour that surrounds a lacuna (figures 1 and 6). Because of the multiple meanings of the word “neutral”, the author of this paper proposes calling this option the 32

Eve Bouyer


and in the 1940 on


and Udina most likely have a completely


or “background colour”






A second option is

In most instances, there is a drastic

choosing the colour that

difference between the predominant

predominates on the whole

and the underlying options, but with

object (figure 2). The author of this

some artworks, they can be the same

paper proposes calling this option the

colour (figure 4).

predominant colour. This corresponds

Aside from these three options,

to the definition of neutral tint

one can otherwise choose colours

provided by Ségolène Bergeon, who

extraneous to the original.

gives a good example: Pietro Perugino’s

Indeed, when choosing one of the

Resurrection from a predella with

original colours seems difficult or

scenes of the life of St Jerome, in the Louvre, where grey was chosen for its predominance in the scene [21]. A third option is choosing a colour that lies under the original surface, and that was not necessarily visible when the object was in pristine condition (figure 3). The author of this paper proposes




underlying colour. This colour can be that of the support medium (wood, canvas, arriccio, Figure 3 • Basin with the Presentation of the Head of Pompeo to Caesar, majolica from Casteldurante, ca 1535–1540; International Museum of Ceramics in Faenza, ac. n° 10570 (M. Pedicini donation, 1960) © Faenza, Museo Internazionale delle Ceramiche

Figure 4 • Mina’i jar, polychrome stonepaste from Iran, 12th–13th century; The Metropolitan Museum of Art, ac. n° 17.120.183 (Bequest of Isaac D. Fletcher, 1917) © The Metropolitan Museum of Art (www.metmuseum. org)

Figure 5 • Bowl with Griffin, luster-painted earthenware from Egypt, 11th century; The Metropolitan Museum of Art, ac. n° 1970.23 (Louis E. Seley gift, 1970) © The Metropolitan Museum of Art (www.metmuseum.org)

visually inappropriate, it is possible to

Annunciation, both conserved in the

show an undertone, such as beige,

select a new one that resembles a

National Gallery and showing grey

taupe, off-white etc.

“blend” of the colours surrounding

neutral integrations [9].

the lacuna (figure 5). The author of

The 1990 restoration of Piero

in the literature, and apparently had a

this paper proposes calling this an

della Francesca’s frescoes in Arezzo,

great success in Germany as early as

intermediate colour, term used in a

particularly the scene depicting the

the 1920s [8; 10]. It was devised with the

paper by Meg Loew Craft [23]. An alien

victory of Constantine, which shows

good intention of being unobtrusive:

colour is applied to the object, but it

grey and beige neutral integrations

because grey is supposed to be the

still somewhat ressembles the original

(colour photographs can be seen on

result one would obtain by mixing all

colours. In some cases, especially when

an interactive online feature

colours together, it was thought to be

the object shows a high contrast ratio,

it might result in a dirty-looking colour,

fresco cycle in the Neues Museum


which is not very pleasing to the eye



of Berlin: Aus dem Sagenkreis

criticised. Already in 1940, the Manual

The fifth and last option the author

der Edda, by Gustav Heidenreich,

on the Conservation of Paintings

identified is an extraneous colour

Gustav Richter and Robert Müller;

called it “a fiction: it will always assume

which is not chosen for having a



the complementary tones of the

resemblance to the original colours

World War, it shows today grey

neighbouring colours, thus introducing

but because it is supposed not

neutral integrations.

an alien element into the painting” [20].

to influence their perception. We

Here, we approach the definition of

The same observation was made in

propose to call this an unrelated

neutral colour from fields other than

1968 by Ruhemann: “However grey a

colour. In practice, it is often a grey

conservation. To colour specialists,

tinge may be in itself, the neighbouring

or beige colour. Some interesting

neutral precisely means achromatic

or surrounding colour will give it, by

examples are:

colours: pure black, pure white and

contrast, a more colourful hue; and

The 1940 restoration of Lorenzo

pure greys. Interior designers generally

the most important rule is not to

Monaco’s Coronation of the Virgin,

include as well colours similar to

introduce any alien shade into the

and the 1982 restoration of Duccio’s

achromatics but that nevertheless

painting; if grey is not in it, none must

Neutral grey is frequently mentioned



The 2000s restoration of a



compatible with all original colours . This usage was however soon

The bad reputation of neutral retouching


Not everyone considers this option

Conservators tend to understand the

as neutral; Jilleen Nadolny calls it

term as it is used in chemistry, where

“suggestive differentiated retouching”

neutral has a completely objective

be added”

. These comments have


something in common with those

same lacuna include:





will always be cases where it is required



terminology of conservation remain

because a reconstructive retouching

fully – reconstructive.

and implies something completely

to be solved: the word “neutral”

would be deeply conjectural and thus

Finally, a neutral retouching does

innocuous, without any effect. This is

is one example among many. This

unethical. In cases of deep conjecture,

not necessarily mean a flat uniform

of course completely impossible with

paper highlights the term’s range

any attempt at reconstruction would

colour. Some authors acknowledge

reintegration issues: any choice will

of meanings and proposes specific

necessarily be a personal, and thus

that neutral can correspond to

always affect perception of the artwork.

terms for distinguishing the various

partial, reinterpretation, liable to

heterogeneous colours, notably those

But if we consider the term’s other

neutral options. It also provides

deceive the general public and

obtained with divisionist retouching

uses – in geopolitics, law or sociology

suggestions for using and interpreting

misguide art historians in their stylistic

techniques [8; 21]. It might be tratteggio,

for instance – neutrality does not

the adjective more accurately, but

or iconographic analyses.



necessarily mean having no impact at



Because of its aesthetic implications,

(figure 6) or other means of making

all but rather “not taking sides”, staying

terminological consensus will require

neutral retouching is not an easy

colours less flat (figure 4), such as the

as impartial as humanly possible.

much more critical thinking. Maybe it

exercise. Choosing a solution that is

In this sense, the term “neutral” might

would be best to simply banish the

the least disruptive requires either

“Neutral” can mean almost anything

be valid. Indeed, any neutral retouching

term? But what should replace it?

natural talent or real effort to evaluate

to conservators (table 1). Should the

will strongly influence the appearance of


examples and assess possible options.


sponge technique.







written by Sheila Landi; the author of

The 1958 restoration of the

term, which is often criticised and placed

the artwork: it is not neutral as a visual

Aesthetic displeasure is not an

To sum up, neutral retouching is

this paper thinks that she might have

main panel of Giovanni da Milano’s

within quotation marks, be banished

fact. But it can be considered neutral as

argument against neutral retouching.

sometimes required from an ethical

had this understanding of the term

polyptych conserved in the Museo

from the field of conservation? At the

a human action, in that it expresses the

Certainly, it should not be used

point of view, but is a challenging

“neutral” in mind when she reacted

civico del Prato, qualified as “matching

very least, it should be used with caution.

desire to avoid influencing the viewer’s

systematically for all types of losses,

exercise. It is therefore essential for

to Rita Udina’s post.

neutral” by Marco Ciatti .

Its use might be especially problematic

opinion on what used to occupy the

as was the case at certain points in

conservators to get past prejudices

The 1972 restoration of two

when qualifying nouns that imply a

lacunas and, in the meantime, to simply

the history of conservation: doing so

against neutral retouching in order to

issues, executing a neutral retouching

panels by Ugolino di Nerio (Isaiah

concrete visual fact, such as colour, tone

admit that the truth is unknown.

would neglect the artwork’s aesthetic

give it the attention it deserves.

does not necessarily mean filling in all

and a diptych with Saints Simon and

or tint. Indeed, as claimed by several

the lacunas of a given object with the

Thaddeus), both conserved in the

authors, no colour/tone/tint can really

same colour. It can also correspond

National Gallery: they are considered

be neutral. Even if a pure grey is neutral

to using several colours depending

neutral by some authors because of

in isolation, it will not remain so when

on the areas. It can be one colour per

their flat unmodulated colours

placed in a colourful context, which will

lacuna (figure 6) or several colours in

Other examples can be seen in

induce chromatic interactions. Thus, it

the same lacuna that indicate the lost

the European Illustrated Glossary of

might be best to avoid such a wording.

shapes without reconstructing details,

Conservation Terms for Wall Paintings

But maybe the adjective could keep being

as suggeted by Dimitrios Doumas [26].

and Architectural Surfaces [16] and in a

used when describing a human action,

paper by Dimitrios Doumas

such as retouching or reintegration?


Apart from these purely chromatic



integration with several colours in the

find it aesthetically unpleasant, there


. Indeed, it is partially – but still not

Figure 6 • Bowl with Susanna and the Elders, majolica from the Fontana workshop in Urbino, ca 1545– 1550; International Museum of Ceramics in Faenza, ac. n° 6156 © Faenza, Museo Internazionale delle Ceramiche

potential. Even if as a conservator you



Eve Bouyer






[9; 17]

Table 1 • Summary of neutral options TYPE OF COLOUR


surrounding matching the original

predominant underlying

extraneous to the original

intermediate unrelated


the same colour everywhere

flat uniform

several depending on the areas


The bad reputation of neutral retouching


REFERENCES [1] Bourgeois, Brigitte – La fabrique du vase

21 (2000), pp. 43-57.

[15] Ruhemann, Helmut – Technique and

[20] Manual on the conservation of paintings.

Vol. 2, Washington DC: The American Institute

grec. Connaître et restaurer l’antique dans



[10] von der Goltz, Michael – Is it useful to

Ethics of Retouching. In RUHEMANN, Helmut

Paris: International Institute of intellectual Co-

for Conservation of Historic & Artistic Works,

l’Europe des lumières. Technè. N° 32 (2010),


restore paintings? Aspects of a 1928 discussion

– The Cleaning of Paintings, 1968, pp. 240-263.

operation, 1940, pp. 22 and 107.

1994, pp. 73-88.

pp. 5-10.

[17 Nov. 2017].

on restoration in Germany and Austria. In

[16] Weyer, Angela; Roig Picazo, Pilar;

[21] Bergeon, Ségolène – «Science et

[24] Giboteau, Yvonne; Zumstein, Isabelle;

ICOM Committee for Conservation. 12th

Pop, Daniel; Cassar, Jo Ann; Özköse, Aysun;

patience» ou la restauration des peintures. Paris:

Vinçotte, Armand – Considérations sur la

Vallet, Jean-Marc; Srša, Ivan, ed. – EwaGlos.

Editions de la Réunion des musées nationaux,

restauration de céramiques archéologiques,

1990, pp. 194 and 224-225.

notamment sur la restitution de la couleur.

[2] Ciatti, Marco – Approaches to Retouching and





[6] Boito, Camillo – I restauri in architettura.


In CRIPPA, Maria Antonietta, ed. – Camillo


Italy. In Early Italian Paintings: Approaches to

Boito, II nuovo e l’antico in architettura. Milan:

September 1999. Vol. I, London: James & James,


Conservation. Proceedings of a Symposium at

Jaca Book, 1989, pp. 122-123.

1999, pp. 200-205.


the Yale University Art Gallery (April 2002). New Haven:Yale University Press, 2003, pp.191-207. [3]

Schädler-Saub, Ursula

– Teoria


metodologia del restauro. Italian contributions


[5] Wikiart – Death of the Knight of Celano.

Meeting. Lyon, 29



[22] de Lapérouse, Jean-François; Stamm,

Conservation-restauration des biens culturels.

[7] Boito, Camillo – Conserver ou restaurer?

[11] Brandi, Cesare – Théorie de la

(1893), translated from the Italian by Mandosio

Restauration, translated from the Italian by

SURFACES. Petersberg: Michael Imhof Verlag,


at The

[25] Institute for Advanced Study – Interactive

Jean-Marc. Saint-Front-sur-Nizonne: Editions de

Déroche, Colette. Paris: Editions du patrimoine,

2015, p. 330.

Metropolitan Museum of Art. In Glass and

model:The Legend of the True Cross (Piero della

l’Encyclopédie des Nuisances, 2013, pp. 46-47.


Ceramics Conservation 2007: Interim Meeting

Francesca). Available at: http://projects.ias.edu/

of the ICOM-CC Working Group, August 27–

pierotruecross/pieroimages.html [17 Nov. 2017].

30, 2007, Nova Gorica, Slovenia, Nova Gorica:

[26] Doumas, Dimitrios – Reconstructing

to conservation in theory and practice. In

[8] Nadolny, Jilleen – History of Visual

[12] Mora, Laura; Mora, Paolo; Phillipot, Paul

Conservation and Preservation. Interactions

Compensation for Paintings. In Hill Stoner,

– Conservation of Wall Paintings. London:

between Theory and Practice. In memoriam

Joyce; Rushfield, Rebecca, ed. – Conservation

Butterworths, 1984, pp. 310-312.

Alois Riegl (1858-1905). Firenze: ICOMOS,

of Easel Paintings. Oxon: Routledge, 2012, pp.

2010, pp. 81-94.


[13] Baldini, Umberto – Teoria del restauro e unità di metodologia. Firenze: Nardini

[4] Conti, Alessandro – A history of the

[9] Ackroyd, Paul; Keith, Larry; Gordon,

restoration and conservation of works of art.

Dillian – The Restoration of Lorenzo Monaco’s

[14] Ruhemann, Helmut – La technique de la

Oxford: Butterworth-Heinemann, 2007, pp.

‘Coronation of the Virgin’: Retouching and

conservation des tableaux. Mouseion.Vol. 15, n°


Display. National Gallery Technical Bulletin. Vol.

III (1931), pp. 19-21.

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[17] Nicolaus, Knut – Manuel de Restauration des Tableaux. Köln: Könemann, 1999, p. 291. [18]LinkedIn’s Conservator-Restorer group – The Diplomatic Neutral Colour. Available at: https://www.linkedin.com/groups/94889/9 48

Karen; Parry, Vicki – Re-examination and of



Goriški muzej Kromberk, 2007, pp. 112–119.

N° 4 (1992), pp. 12-14.

the Image: A discussion on the Effectiveness

[23] Loew Craft, Meg – A visual review

of Restoration Methods for Painted Surfaces.

of compensation philosophies for Islamic

Theory and Practice at the Benaki Museum

ceramics. In Loss Compensation: Technical

Conservation Department. Mouseio Benaki.


and Philosophical Issues. Proceedings of the

Vol. 10 (2010), pp. 83-103 . Also available at:


Objects Specialty Group Session, 22nd Annual


conservation-neutral-colour-field/ [17 Nov. 2017].

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Anatypo_Doumas.pdf (17 Nov. 2017].

89-6223512192315064322 [17 Nov. 2017]. [19] Udina, Rita – The Diplomatic Neutral Colour.



The bad reputation of neutral retouching


Keywords Pigments; Painting technique; Mattia Preti;


Original-replica-copy; Four Evangelists; Inpainting

1. INTRODUCTION This project focuses on two series of paintings representing the four

Figure 1. • Four Evangelists, Our Lady of Carmel Church, before and after conservation

Evangelists. These sets of four paintings

Mara Kolić Pustić Breska Ficović (3)


| Carlo Galliano Lalli


| Nancy von

decades. Prijatelj made some analogies

buildings in the inner city of Dubrovnik:

to Mattia Preti’s work and suggested an

the confraternity church Our Lady of

attribution to his workshop.

quality was revealed. A year later, the

1.1 Mattia Preti

also included into the project with

Carmel (Karmen), and St Blaise (Sv.

1. Croatian Conservation Institute (HRZ), Conservation Department Dubrovnik, Batahovina bb, 20 000 Dubrovnik, Croatia; mpustic@h-r-z.hr 2. O  pificio delle Pietre Dure e Laboratori di Restauro di Firenze, viale Filippo Strozzi 1 – Fortezza da Basso, 50129 Firenze, Italy; carlogalliano.lalli@beniculturali.it 3. Senior Art Historian, Avenue des Cèdres 6, 1640 Rhode Saint Genèse, Belgium; nancy.vonbreska@skynet.be

of the series of Evangelists from Our

were located in two Baroque ecclesiastic

Vlaho), the church honoring the patron saint of the city. Beside the article by

Mattia Preti (Taverna, Italy, 1613 -

Croatian art historian Kruno Prijatelj1

Valetta, Malta, 1699) was a renowned

from 1981, there was not much more

Italian baroque artist and Knight of

to be found about these paintings for

the Maltese Order. His elder brother Gregorio was also a painter active in


Rome. Mattia joined him and they

Two series of Four evangelists, eight canvasses, formerly belonging to two Baroque

The importance of each and every step

churches (St Blaise and Our Lady of Carmel), attributed to the Baroque artist Mattia

of the conservation process leading to

Preti, have been restored by the HRZ, Croatian Conservation Department Dubrovnik

the final phase, the retouching, and the

in cooperation with Opificio delle pietre dure (Florence).

worked together, but very quickly

Lady of Carmel and their excellent paintings from St Blaise church were the intention of a simultaneous work and research. It was clear from the beginning that there was some kind of a connection, but at the same time, there were significant differences between the two series that needed to be clarified.

he became more popular and was commissioned to execute prestigious

1.3 Evangelist paintings by Preti in

choice of the retouching method was

artworks. In 1653 he moved to

Italy and Malta

The international interdisciplinary restoration and research project determined

demonstrated. It was proved that the

city of Naples until 1661, when he

the original prototype, explored the question of copies-replicas as well as possible

two series of paintings were following

origins within the same workshop. The stratigrafic analysis was performed and


transferred to Malta, where he spent

subsequently compared to the vast data base of Mattia Preti paintings (from

contributed in the execution of a mimetic

Taverna) in the laboratory of the Opifico delle Pietre Dure.

kind of inpainting. Details of the paintings

The results of the research and the conclusions regarding the copy-replica-original

photographed in different phases of the

topic were presented as well as the specific characteristics of the pigments used for

restoration work were presented and

creating the Evangelist-paintings. The retouching from the former 19th and mid-

the chosen retouching technique was

20th century restorations was presented and discussed.

explained and substantiated in detail.




The art historian Prijatelj was familiar with the painting Four Evangelists

the rest of his long and very active life.

from the Galleria Abatelis in Palermo.

1.2 Croatian Conservation Institute

almost identical paintings to the


Dubrovnik Evangelists emerged in the

In 2005 the Croatian Conservation Institute (HRZ) began the restoration

However, in the meantime other,

Catalogo Reggionato by John T. Spike2. At the beginning, only one painting

of Mattia Preti’s Evangelists-series

first intervention, the linen support

found on all Preti’s paintings from that

was known: a St Mark, in Cosenza,

was mended with patches and in

period (1661-1699).

Italy. It seemed to be identical as the

1950-ies a wax and resin lining was

one from the Our Lady of Carmel.






preparations of all eight paintings from

Spike suggested that the painting

Two different interventions were

Dubrovnik consist of similar, almost

belonged to the early Maltese period

also confirmed by two different sorts

identical materials: earth pigments,

of the painter. Besides that, he also

of fillings. In the Austro-Hungarian

ochre, calcium carbonate, some iron

mentioned, two copies of Preti’s

intervention a brown toned varnish

oxide, carbon black and tiny chips of

Evangelists St Mark and St Luke, from

was applied. In 1950-ies, that varnish

glass in an oily binder applied in two

Malta. At that point, although he was

was removed only in some, mostly


not familiar with the existence of the

brighter areas and in some areas, it

Differences between the Dubrovnik

two complete series in Dubrovnik, he

was not removed at all. The fillings

series have been found only in

rightly came to a conclusion that the

were applied in all damaged areas


St Mark in Cosenza was a part of a

and the retouching was executed

Dubrovnik paintings, however, do not

series of four paintings representing

accordingly to the level of cleaning.

contain any microfossils. Therefore, it

the four evangelists. As to that date,

Some filling and retouching was

was concluded, despite the previous

there was no trace of St Matthew and

spreading over the original.

assumption, that Maltese materials

fundamental for a reconstruction of the iconography of the series.

granulometry. The

1.4 New discoveries/originals-copies

part of a quite popular original set of


paintings by Mattia Preti.

During the project, more paintings 2. MATERIALS AND METHODS

were discovered. Beside St Marc in Cosenza, the existence of another

During restoration works it was

original by Preti, a St John, also in

established that the original dimensions

Italy, was confirmed. An information

of all eight paintings were the same. In

about a sold St Luke in Munich,

case of the Carmel-series the linen

pictured only in a black and white

support has a 10 cm broad, stitched

photo, was also found. Furthermore,

addition along the right border. In

the remaining two copies from Malta

comparison, the St Blaise series has

were traced. These discoveries shed

been painted just on one wider piece of

new light on the importance of the

canvas. Interestingly, the two paintings

Mara Kolić Pustić | Carlo Galliano Lalli | Nancy von Breska Ficović

in Italy, have the same dimensions and,

2.1 Earlier interventions

besides that, they have the same sort

The research has shown that there

of support as the Carmel series: the

had been two earlier interventions on

one with a 10 cm stitched addition. If

both series of paintings. An Austro-

we compare the 2 Dubrovnik series

Hungarian, around the beginning of

and the Italian one, they seem to be

20th century and a second one, done

exactly the same up to the smallest

in Zagreb in the 1950-ies. During the

detail. The only difference has been detected in the fringe on the forehead of the saint. As the UV fluorescence

Dubrovnik series.

2.2 Stratigrafic analysis

Figure 2. • Four Evangelists, St Blaise’s Church, before and after conservation

two Dubrovnik series, making them

belonging to the evangelists’ topic


were not used in the execution of the

St John, the Dubrovnik paintings were



The comparative analysis of the

As for the pigments in paint layer,

materials used by Mattia Preti was

the situation was similar. For example,

executed in the Opificio delle Pietre

the flash colour consisted of: lead

Dure in Florence, by Carlo Lalli.

white, with some green earth and


carbon black, red lake, earth pigment

assumptions, Maltese materials were

and vermilion particles. The presence

to be expected. Earth pigments from


Malta are rich in microfossils and were

crystals in lead white was particularly







Figure 3. • D  etail of the forehead, St Mark the Evangelist, Our Lady of Carmel Church: a) during cleaning in visible light; b) x-ray during cleaning; c) during cleaning in UV light; d) after conservation

and x-rays suggested, and the different character of material has confirmed, originally that difference did not exist at all. It was a consequence of a later intervention.

Baroque master mattia preti and his workshop- Two series of four evangelists from dubrovnik



the original one, the inpainting process will be burdened by issues that should

Figure 4. • Taverna, the microfossils are visible; c) St Mark the Evangelist, St Blaise’s Church, Dubrovnik; d) St Mark the Evangelist, Carmel Church, Dubrovnik

It is important to stress that all

have been resolved in earlier phases

previous phases of conservation-

of work and the conservator will

interesting. The very same ingredients

in preparation and in the paint layer.

restoration work are the ones that

be confronted with the challenge to

were actually found in the flesh colour

In that case the art historians and

contribute and define the final

“cover” and “mask” those issues with

on all paintings of both series.

painting conservators are unanimous

inpainting phase. Each and every phase

colour in final phase of work. Even if

The black pigments appeared to be

in conclusion that the St Blaise series

of work, when done properly, reduces

we are brilliant in that skill, the result

interesting too.The presence of a rare

was painted by another hand and can

and simplifies the final retouching

will never be as good as the one when

carbon black with high percentage of

be considered as a workshop replica.

process. If we do not manage to do

all phases are done thoroughly.

Sulphur was detected in both series.

In respect to that - the paintings

the uniformed and thorough cleaning

As for the choice of a retouching

However, in case of the blue colour,

from Malta can be considered as later

up to a chosen point and leave some

method to be done, the decision was

another black pigment was used - the

copies with different proportions,

“problems” to be resolved by the final

quite simple. The missing areas were

bone black. It was added to indigo

absence of architectural elements

inpainting phase or if we do not blend

not too big or hard to define, and

along with the lead white. Again, the

and completely different painting skill.

in the character of the filled area into

having more paintings with the same

same pigment mixture was found on both series of Dubrovnik paintings.

Figure 5. • Detail of St Luke’s eyes, St Luke the Evangelist, Our Lady of Carmel Church: a) after filling; b) after filling in raking light; c) after conservation

motive made it even easier to choose

the complete integration of missing areas into the original as a concept of a retouching. A good example of a potentially puzzling situation could be the area of the St Luke painting. The forehead of the Child could be interpreted as either damaged or left as unfinished on purpose - because St Luke, the painter, has not yet finished his work. In this case, with more paintings to compare, it was quite certain that we were not dealing with a superficial damage, but with an intentional “unfinished” area of a painting. The filling was based on plextol binder and brown earth, pigment filler close to the original preparation in tone.


high quality stable pigments, Canada balsam and - optionally - a small quantity of varnish is needed. If the granulation of a pigment is not fine enough, it is necessary to grind it until it is. Earlier, shellsol T was used to wet the pigments during the grinding procedure, but distilled water and/or ethanol instead, seem to be more efficient and easier to control. It’s interesting to notice how much the tone sometimes changes in respect to a different granulometry. It’s good to keep that in mind for some certain cases when we do not need the transparency, but do need a darker tone. For example, on these paintings, in some situations the blacks were simply not black enough.

3.1 Underpainting

2.3 Analysis conclusions

The procedure of working with

In respect of all the findings – the

gouache can be described in several

following conclusion could be made:



The measures of all Dubrovnik as well

1. We start with a middle tone for

as the Italian paintings are the same.

a certain zone; 2. It is applied to the

The linen support with the stitched

whole area of the same colour; 3.The

addition on the right side is the same

next step is building up the shadows

for Carmel Dubrovnik series as well

or lights in a way that a similar

as for the two Italian paintings. These

transparent layer will be needed for

two series can be considered as work

the whole area to blend it in into

of Mattia Preti and his assistants and

the original; 4. After completing the

therefore, one could be a replica of

gouache underpainting, the first layer

the other. The St Blaise series was

of varnish is applied with a brush.

created on base of the same drawing,

very similar if not identical materials




colours, a

maximum possible quantity of pigment up to a saturation of the binder is needed. If there is too much binder, the colours tend to be less soluble with time and to transparent and shiny. The Canada balsam tends to get denser with time. Because its consistency is crucial for getting the right ratio of pigment and balsam, it’s good to know that Canada balsam can be successfully diluted with some ethyl-l-lactate. Once made,the colours are positioned on a plexiglas palette where they dry and can be resolved by different sorts

probably in the same workshop but not in the same time, but consisting of


Figure 6. • D  etail of the forehead of the Child, St Luke the Evangelist: a) Our Lady of Carmel Church, gouache underpainting; b) Our Lady of Carmel Church, after conservation; c) St Blaise’s Church

Mara Kolić Pustić | Carlo Galliano Lalli | Nancy von Breska Ficović

3.2 “Colori a vernice”- glazing

As for the final glazes, a selection of

of mediums (for example ethyl-l-lactate and acetone mixture).

Baroque master mattia preti and his workshop- Two series of four evangelists from dubrovnik



Evangelists in the Oeuvre of Mattia Preti, The

difficile, un ritorno trionfale” a cura di

[1] LALLI, Carlo Galliano; VON BRESKA-

Croatian Conservation Institute, 2009.

Caterina Caneva, ed Edifir Firenze, giugno

FICOVIĆ, Nancy; INNOCENTI, Federica;

[4] T. SPIKE, John – Catalogo ragionato dei di-

2006, pp. 48,49

KOLIĆ PUSTIĆ, Mara – Le due serie

pinti, Centro Di, 1999.

[8] Museo degli Uffizi, “La Medusa di Ca-

[5] PRIJATELJ, Kruno – Prilog odjeku

ravaggio restaurata” a cura di Caterina

Caravaggia u Dalmaciji, Peristil. Vol. 24

Caneva. Saggio restauro ed retablo, Roma

(1981), pp. 72-76


dei quattro Evangelisti di Mattia Preti a Dubrovnik: un progetto multidisciplinare e di Figure 7. • Detail of the parchment, St John the Evangelist, Our Lady of Carmel Church: a) after filling; b) after underpainting; c) after conservation

dell’Opificio e l’Istituto croato di Restauro.

The role of the more volatile solvent

motivated by some particular situation,

same drawing was used as a base

is to control the speed of drying

it is important to stress that presenting

for the paintings, the same materials

[2] KOLIĆ PUSTIĆ Mara – Tragom dubro-

which becomes important in applying

and discussing the “common”, “simple”

were applied and yet, the result is

vačkih naručitelja slika s područja južne Italije

of every next layer to avoid dissolving

situations can sometimes be left in a

not slightly, but obviously different.

u baroknom razdoblju. Umjetnost i naručitelji,

the previous one. It is also important

shadow and can be taken for granted.

However, much a conservator tries

to have patience, to let each layer dry

In fact, the “classical”, “usual” procedures

to be “invisible” and to let the work

completely before proceeding.

need to be shared more. They are

of art be dominant, his contribution is

Furthermore, some brown colours

common and simple for those who

always present and it is always a kind

tend to be less soluble once they

know how to perform them, but not

of an interpretation that had been

are dry on the palette. For such

that simple for those who do not yet

chosen. The retouching intervention

cases, sometimes it helps if a drop of

have the knowledge and the skill.

becomes a part of a “life” of a work

varnish is added to the mixture while preparing the colours.

The best way to learn, beside all the explanations and conferences, is simply

These colours do not darken with

to watch someone more experienced

time. If they do change, they get a bit

doing it. On the other hand, however

brighter, and, if necessary, it is quite

experienced we are, there is always

simple to darken them some more.

some space left for improvement and modifications. It can always get better. Finally, it is not only important to make


a right choice of the materials that we The described retouching method

are going to use.We also need to know

was introduced to Conservation

how to use them and that can make a



huge difference. There is no guarantee

Florentine colleague Stefano Scarpelli.

of doing a good job just because having

It’s not a revolutionary method, on

used some suggested quality materials.

the contrary, it is a classic.

The two Dubrovnik series are a perfect



Although,it is quite obvious that this was not the case of some specific approach, 44

collaborazione tra il Laboratoria Scientifico OPD Restauro. Vol. 26 (2014), pp. 231-248

Zbornik Dana Cvita Fiskovića. Vol 3 (2010), pp.101-109 [3] KOLIĆ PUSTIĆ, Mara, ed. - The Four




Official website http://www.h-r-z.hr/en/index.php/spotlight/vijesti/1090-presentation-of-the-conser vation-project-qthe-four-evangelists-in-the-oeuvre-of mattia-pretiq [7] SCARPELLI, Stefano”Il Restauro” ghirladnaio di Vallombrosa, “un restauro

[9] Kermes rivista, “Una tempestiva risposta per la salvaguardia del patrimonio artistico di Dubrovnik” [10] Gli Uffizi, Studi e ricerche, No 14 “Nota di restauro” Cena con sposali di Gerardo delle Notti. I restauri dell’attentato, construtivo 1993-1995, ed Centro Di, Firenze 1995, pp.21-22

of art. We need to be aware of that and try to make the best of it.

Figure 8. • Detail of the eagle, St John the Evangelist: a) Our Lady of Carmel Church, after filling; b) Our Lady of Carmel Church, after underpainting; c) Our Lady of Carmel Church, after conservation; d) private property, Italy

NOTES 1 Prijatelj Kruno Prijatelj, - Prilog odjeku Caravaggia u Dalmaciji, Peristil 24, Zagreb (1981), p. 73 2 John T. Spike, Catalogo ragionato dei dipinti, Centro Di, 1999 3 Filling: 10g binder (Lascaux Akrylkleber 498HV) + 40g water + 40g filler (pigment Iseo Braun - Kremer) 4 W&N selection of gouache colours with good stability characteristics is the one that was used

example to make that point: As elaborated, the same composition,

Mara Kolić Pustić | Carlo Galliano Lalli | Nancy von Breska Ficović

Baroque master mattia preti and his workshop- Two series of four evangelists from dubrovnik


Keywords Girolamo da Santa Croce, Panel painting,


Mimetic retouching, Age-related craquelure,

the Baptist with three musician angels


below his feet.

Canada balsam

The side parts of the composition display a group of 36 figures which includes


saints, among others. The whole is The All Saints is a tempera painting Girolamo


da in

Santa 1540

Croce as


altarpiece for the Church of All Saints

1. C  roatian Conservation Institute (HRZ), Dubrovnik Department for Conservation, Batahovina bb, 20 000 Dubrovnik - Croatia; katarina.ak@gmail. com 2. Arts Academy of the University of Split, Zagrebačka 3, 21000 Split - Croatia; sansustic@gmail.com


prophets, patriarchs, female and male



Katarina Alamat Kusjanović (1) | Sandra Šustić (2)

surrounded by St. Jerome and St. John

on the Island of Korčula (Croatia).

It was painted on a relatively large

topped by three arches and the Holy

wooden support (219 × 187 cm),

Spirit represented by a white dove.

consisting of six horizontal boards.

Horizontal and vertical accents of

Saint Peter, depicted as the Pope,

the composition give an effect of

stands in the composition’s center

orderliness and repose (figure 1). [1]

Figure 1 • The All Saints by Girolamo da Santa Croce (1540) before and after restoration. Photo © Vlaho Pustić / Ljubo Gamulin

Abstract A project concerning the conservation and restoration of Girolamo da Santa Croce’s All Saints (All Saints’ Church, Korčula, Croatia) was carried out by the Dubrovnik Department of the Croatian Conservation Institute (HRZ) from 2013 to 2016. The treatment was primarily undertaken because of structural problems, since the original painting materials had become increasingly unstable. Moreover, the materials applied in previous interventions had aged poorly, resulting in overall degradation of the paint layer and thus compromising the proper reading of the artwork. Along with the stabilization of the panel and the paint layer, the inpainting (retouching) process turned

1.1. Physical history of the painting

out to be the most complex part of the restoration treatment. While relatively small lacunae were distributed over the entire surface of the painting, the lower area of the composition - depicting bicoloured floor tiles (pavement) – had sustained major material loss. The visual impact created by the pronounced cracks turned out to have a crucial effect on the viewer’s colour perception, not only 1 Head of the project: Katarina Alamat Kusjanović ; contributors: Antonio Blašković, Ivana Ćustović, Elio Karamatić, Mara Kolić Pustić, Sanja Pujo, and Sandra Šustić

in the pavement area but also in all the painting’s bright parts. Furthermore, the smooth texture of the panel and the consequent colour reflection required outstanding precision in the retouching process as well as the use of the finest materials in order to achieve credibility for the reconstructed areas.

and its influence on the decisions in retouching

Historical records found at the Archive




Figure 2 • D  etails of the painting before treatment. Note the severe flaking of the paint layer. Photo © Vlaho Pustić

materials in uncontrolled and varying

dark residues in the cupped paint

climate in the church along with the

fragments as a consequence of the

inadequate cradle mounted on the

consolidation and cleaning performed

2.1. The effect of craquelure on the

contrasting paint areas are used by

back of the panel, have contributed

in previous interventions. [3]

visual perception of All Saints

Santa Croce to depict the floor on





of the underlying image. Simple

to the development of particularly

The perceptual effect of craquelure

The pattern of cracks is a visible

the All Saints – the decorative tile

dense age-related cracks in the paint

turned out to be of the outmost

record of the physical tensions

pattern was painted with two colours

and primer layers.

importance in forming a retouching

within the structure of the painting

of different values – lighter (white) and

The visual impact of the cracking is

strategy. While relatively small lacunae


dependent upon the choice

darker (orange). The simplicity of the

highly pronounced - especially in the

were distributed over the entire



geometrical forms – lacking any figural

bright areas of the composition. This

surface of the painting, the brightest

construction employed by the artist

elements – has contributed even

is due to the build-up of particularly

area of the composition - depicting


. The literature explaining the

more to the pronounced perception


importance and characterization of

of all irregularities of the paint layer,

cracks was reviewed by Keck (1969)

especially the cracks on the white tiles.

The aim of this paper is to examine

and Bucklow (1997). Namely, the

However, the contrast between the

the degree of finishing necessary to

first records are due to artificial

cracks and the underlying image (the

create an overall balance that will

craquelure created by the art forgers

floor) interferes with the perception

very bad (…) the paint detaches from

appreciate the condition of the paint



of the contrasts between the tiles.

the wood and slides down.“ Despite the

layer and the age of the painting.

while the general descriptions of the

This leads to the conclusion that



shape of the patterns were recorded

the formation of the craquelure has

of mimetic retouching in such a

by Stout (1977). More studious

gradually compromised the intention

demanding appearance of the original

observations are of Marijnissen in

of the artist. Yet, on the other hand, it

paint layer will be discussed as well.

judging the authenticity of the artwork

brings out the role of the craquelure as

(1985), and of Bucklow (1994, 1997,

substantive element for achieving the

1998, 1999, 2000) in analysing the

precise tonality in mimetic retouching.

association of cracks with the artist’s

Thus a close inspection of the

practice and their perceptual effect

shape and the characteristics of the

2013 – severe flaking and increasing

on pictorial image. [6] The result of this

craquelure has been made. It was

instability of the paint layer were

study made evident that the crack

manifest that the direction of the crack

again evident on the entire surface.

network - although subconsciously

lines has approximated right angles

In addition, the materials applied

filtered out as irrelevant - has a large

typical of age-related cracks. The

in the 1977 intervention had aged

effect on the apparent tonality, i.e.

shape of the cracks is quadrangular -

considerably, resulting

it visually darkens and flattens the

very usual in the paintings from the


renaissance period – constituting a

Department in Split made evident

A detailed technical study of the

that the painting has undergone

support and the paint layer indicated

significant restoration treatments in

that the artist’s original technology

the past, specifically due to the severe

was quite poor. The impregnation of

flaking of the paint layer.

the wooden support had lost most





of its adhesive power.The aging of the

describes the presence of a cradle on the back of the panel “probably made in the time of Austro-Hungarian Empire” and excessive damages in the paint layer: “The condition of the painting is

consolidation treatment performed in 1959, the dossier from 1977 reported another extensive consolidation of the paint layer.


Figure 3 • The painting after cleaning and filling of the lacuna. Photo © Vlaho Pustić



sustained major losses (figure 3).


Due to identical structural problems the painting was transported to Dubrovnik




Croatian Conservation Institute in



degradation of the paint layer and thus




reading of the artwork (figure 2).



Katarina Alamat Kusjanović | Sandra Šustić

Figure 4 • D  etail of the original paint layer. Note the size and shape of the crack network. Photo © Sandra Šustić





According to Bucklow , the cracks

fairly fine mesh, with no predominant

will have a large effect where they

orientation, composed of vertical


“All saints are in the detail“: retouching a painting by girolamo da santa croce


and horizontal grooves. Assessment

Although the artist used only two

gradually softened the edges of the

of cracks using a small pointed brush.

brightness of the tiles and flattened

paint was carefully splattered onto the

of this system reveals a distribution

colours to depict the floor - white

glaze, thereby producing blurred

An attempt was made to imitate the

the affected areas to the desired level

reconstructed tiles giving the surface a

linked to paint constitution. It occurs

and orange - it was noticed that each

effects of shading. Each tile was

variety of tones, forms and orientation

(figure 6).

certain antique character (figure 7).

predominantly in areas rich in lead-

preserved tile contains subtle tone

treated separately, while others were

of the lines present in the original

Clearly, this kind of approach required

It is important to note that during

white, such as the flesh tones and, of

gradations within its surface. Thus,

completely covered, in order to

craquelure. This helped to achieve

a lot of preparation and thus the

the reconstruction of the tiled floor,

course, the tiled floor (figure 4).

along with the basic shape of the

avoid unnecessary splattering of the

the persuasiveness and vividness of

retouching could not be executed

the applied layers of paint (especially

tiles, the delicate volume was built

surrounded area.

the entire reconstructed surface, but

rapidly.The splatter technique was used

those from the splatter technique)

most importantly, it decreased the

in the final step as well - pure white

were not piled up, but rather evenly


2.2. Reconstructing the major loss in

as well. This helped to establish the


liveliness of the ambience found in

achieving mimetic retouching was to

the preserved paint layer.

emulate the quadrangular network

Descriptive data on the preserved paint layer beneath the figures


showed that Santa Croce employed

2.3. Emulating the appearance

a geometrical representation of the

of naturally aged paint in glaze

floor with square tiles, similar to


pavement. [9] The square grids are

In order to achieve the illusion of

foreshortened as the lines of the grid

depth, luminosity and patina, evident

get farther away from the viewer. In

on the preserved tiles, the paints

addition, horizontal lines above the

agglutinated with Canada balsam - with

background arches and the lines of

a refractive index approaching that of an

the paved floor are parallel to the

aged oil medium - were chosen for final

picture plan. By tracing the lines of the

retouching. To match the colour of the

floor around the loss - perpendicular

tiles, the pigments such as umber, yellow

to the picture plane - the vanishing

ochre and blacks were indispensable.

point was easily localized and the set

The first step was to spread a

of missing parallel and horizontal lines

highly transparent dark glaze over

was set up in underpainting using

the reconstructed tiles. Due to

Winsor & Newton Designers’ Gouache

the relatively rapid evaporation of

(figure 5).

the solvents used (butanol, ethyl

This initial inpainting was made

lactate) it was not easy to achieve

several shades brighter than the

uniform horizontal strokes. There



were undesirable brush marks and

were painted with almost pure

uneven glaze accumulation on the

white colour in order to retain the

surface, hence the same glaze was

maximum intensity of the surface

gently splattered over the surface

for the upcoming glaze technique.

with a brush. This treatment has


layer. White

Katarina Alamat Kusjanović | Sandra Šustić






Figure 7 • Detail of the painting after retouching. Photo © Ljubo Gamulin

 econstruction of the white tile. Note Figure 6 • R the artificial craquelure. Photo © Sandra Šustić

Figure 5 • T  he All Saints after underpainting. Photo © Croatian Conservation Institute

Nome artigo


distributed on the surfaces. In this

easier to see the potential formal unity

to create the atmosphere proper to a

attempt to misrepresent the artist’s

craquelure could have resulted in

The challenge was imposed by the

manner the final tone contained the

of the work - the operation should stop

Flemish primitive painting will demand

intent in respect to the physical

misrepresentation of the genuine

specific physical characteristics of the

condition of the paint layer and the

paint layer – such as the extremely

actual age of the painting.

subtle texture, the luminosity effect

information of all the previous layers

where hypothesis begins.

The concept

for the realization of an equivalent

characteristics of the painting.

which contributed to the effect of

for the reconstruction of the lower part

integration, an infinitely more elaborate

previously elaborated, the formation

high luminosity.

of the All Saints was strongly supported



and the highly pronounced age-

of the highly pronounced craquelure

related craquelure that the panel has

It was very interesting to observe

by the evidence from the preserved

Of course, Santa Croce’s painting

of the All Saints paint layer has

how the network of artificial cracks

paint layer. As explained in the previous

style is hardly comparable to Flemish

compromised the intention of the

has created a darker tone of the

chapter, the hue reconstruction of the

primitives, but the delicate texture

artist by flattening and darkening the

One of the conservator’s essential

for an infinitely more elaborate

pavement but at the same time

tiles was a straightforward task, while the

of the cracked paint layer and

image. Thus, with respect to the artist

task is to acknowledge the artist’s

retouching, as described by Philippot.

it didn’t corrupt the hue and the

artist’s use of linear perspective enabled

consequent luminosity, required an

intention, the alternative approach



In order to mimic the unique look

intensity of the colour. This helped to

an accurate arrangement of the missing

outstanding precision in retouching

could have been to selectively reduce

overall condition of the artwork.

of a dense textured surface, a careful

“push back“the lacunae and assimilate


and the use of the finest materials in

the visual disruption of the cracks

However, the complexity of the All

selection of the retouching tools,

order to achieve the credibility of the

on the preserved tiles and exclude

Saints retouching demonstrates that

materials and techniques needed to

reconstructed area.

the emulation of the craquelure on

achieving a balance between the

be made. Besides the use of glazes

them into the original paint layer as much as possible.

3.2. The degree of finishing



acquired through time. This called




Both invisible and visible inpainting

One of the basic tenets of retouching

the reconstructed area. However,

artist’s intentions and the condition

and splatter techniques to produce

techniques were at times subjected

is that it must be performed with no

the concealment of the authentic

of the painting is not an easy task.

smooth transition of tones, a crucial

to criticism.

[11, 12]

factor in obtaining the desired tonality

According to Brajer

3.1. Reconstruction as a critical

differences of opinion seem to occur


when we enter into the domain of

Figure 8 • Detail of the floor before and after the retouching. Photo © Vlaho Pustić, Ljubo Gamulin

was the rendering of the artificial craquelure. This helped to harmonize


aesthetics and the choices we made

the retouching with the condition of

compositional losses is considered as

can have a profound effect on the

the painting as a whole.

one of the fundamental issues of the

perception of authenticity of a given

restoration process, highly dependent

object. [13] The high degree of finishing

on the type, placement and function

shown in the retouching phase of

of an object. Due to the liturgical

the All Saints project depended

importance of the All Saints painting,

primarily on the style and physical

the complex damage of the lower

characteristics of the painting.




part of the composition corrupted

In order to further elaborate this

the meaning of the artwork and

argument it is necessary to recall the

[1] FISKOVIĆ, Cvito - Neobjavljena djela

degraded its value.Thus the executed

broad view of Philippot: “If the rupture

Girolama i Francesca da Santa Croce na Visu,

reconstruction was a preferable part

caused in a medieval fresco can often be

Lopudu i Korčuli. Peristil. Vol. 6–7 (1963), pp.

of the intervention course.

filed in by a simple hue – as long as its


According to Mora, Mora and Philippot, the







value and density places it as the proper


constructive level – the importance of a

justifiable as long as it aims in making it

detail, finish, and enamel-like appearance

Katarina Alamat Kusjanović | Sandra Šustić


[2] ŠUSTIĆ, Sandra - Djelovanje Cvite Fiskovića na zaštiti i restauraciji povijesnog slikarstva i skulpture na hrvatskoj obali. Unpublished PhD dissertation: University of “All saints are in the detail“: retouching a painting by girolamo da santa croce


Zagreb, 2016., p. 308-309. [3] BOMFORD, David - Picture cleaning: positivism





Getty Conservation Institute. pp. 331–8 [A


translation of the 1866 text.]

cracks [10 October 2017].

[13] BRAJER, Isabelle - Authenticity and

STONER, Joyce; RUSHFIELD, Rebecca, eds. -

[8] MOHEN, J. P., et al. - Mona Lisa, Inside

restoration of wall paintings: issues of truth

Conservation of Easel Paintings. London and

the painting, Harry N. Abrams inc, New York,

and beauty. In: HERMENS E. and FISKE T.

New York: Routlege, 2013, pp. 481-491, p. 486.


eds. - Art, Conservation and Authenticities:

[4] BUCKLOW, Spike - The description of

[9] ALBERTI, L.B. - On Painting and

craquelure patterns, Studies in Conservation.


Vol. 42, (1997), pp. 129–140.

Greenwood Press,1991.





Material, Concept, Context. London: Archetype Publications, 2009, pp. 22-32. [14] PHILIPPOT, A.; PHILIPPOT P. – The

[5] ABAS, Fazly Salleh - Analysis of

[10] MORA, Paolo et al. – Problems of

Problem of Integration of Lacunae in the

Craquelure Patterns for Content-Based Retrieval.

presentation. In: STANLEY PRICE, Nicholas et

Restoration of Paintings. In: STANLEY PRICE,

Unpublished thesis submitted in partial

al., eds. - Historical and Philosophical Issues in the

Nicholas et al., eds. - Historical and Philosophical

fulfillment for the degree of Doctor of

Conservation of Cultural Heritage. Los Angeles:

Issues in the Conservation of Cultural Heritage.

Philosophy: University of Southampton, 2004.

Getty Publications, 1996, pp. 343–354, p. 345.

Los Angeles: Getty Publications, 1996, pp. 335-

pp. 15-18. [6]

Bucklow, Spike

[11] BRANDI, Cesare - Il fondamento teori- The



Craquelure on the Perception of the Pictorial


the Hamilton Kerr Institute. Available at: https://

co del restauro, Bollettiono dell’ instituto Centrale del Restauro. 1, (1950), pp. 5–12.

342, p. 337. [15] DIGNEY-PEER, Shawn - The imitative retouching of easel paintings. In: HILL

Image, Zeitschrift für Kunsttechnologie und

[12] SECCO-SUARDO, Giovanni - The

STONER, Joyce; RUSHFIELD, Rebecca, eds. -

Konservierung, Vol. 8, n.º 1, (1994), pp. 104-111.

idea of the perfect restorer. In: BOMFORD

Conservation of Easel Paintings. London and

[7] Bucklow, Spike - The Effect of Cracks on

David and LEONARD Mark, eds. - Issues

New York: Routlege, 2013, pp. 607-635, p. 608,

the Perception of Paintings. Official web site of

in the Conservation of Paintings. Los Angeles:


Katarina Alamat Kusjanović | Sandra Šustić

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Keywords Microcrystalline powdered cellulose; artificial accelerated ageing; infilling;


light bleaching;


paper conservation

PREPARATION There are several brands of cellulose powder, each one with its own characteristics in relation to particle size. For this study Solka-Floc 300 ®


was chosen because its particle size Cellulose powder is being widely used in paper conservation to

Rita Udina (1) | Amparo Escolano (2) 1 Rita Udina - Paper & Books Conservation; C. Sant Pere, 24; Premià de Mar – 08330, SPAIN; info@ritaudina.com 2 South Florida Art Conservation; 500 Palm St. Ste 35, West Palm Beach, Florida 33401, USA; aem@sflac.net

conceal stains, fill small losses or gaps in tears, diminish abrasions, and repair

will allow the conservator to pick a

-22 micron- enables a broad range

colour as similar as possible to the

of application methods, providing the

surface of the paper that needs to be

conservator more versatility.


The samples prepared for the

Overall, cellulose is a very stable

ageing tests intended to be as similar


product; but toasting it to give it a

as possible to those that would be

similar material to paper, the visual

certain hue might seem quite a dramatic

used in reality.

damages created by silverfish or tape . Since micro-cellulose is a very

results obtained using it are very pleasant. In order to match its colour to the support in which it is going to be applied, it is common practice to have it toasted on a pan or hot plate. Different toasting times allow various degrees of browning of the powdered cellulose. Preparing the cellulose powder at different tones


method regarding its durability, especially

There are three main methods

when it comes to guaranteeing the

when using powdered cellulose in

best quality and stability of the products

paper conservation:

applied in conservation treatments.This

Tamper the dry powder on top

paper intends to look at the possible

of a layer of adhesive previously

alteration of the cellulose after this

applied to the support.

toasting, the possible side effects and

Mix the powdered cellulose

how to diminish or solve these issues, if

with an adhesive and apply this

at all necessary.

mixture over the paper [4].

Figure 1 • U  n-aged samples, four toasting degrees, and three different mediums (12 samples).

Powdered micro-cellulose is commonly used in the paper conservation lab for filling

determine the possible limitations of

small losses, concealing stains and treating other damages on paper. Its neutral

the use of micro-cellulose powder in

pH, general chemical stability and low toxicity, makes powdered cellulose a very

the long term, some artificially induced

reliable and compatible material, and also proved to be suitable for conservation

degradation tests have been performed.

purposes, like infilling and colour matching of the paper support. However, the

The test results presented in this paper

ageing of this pure powdered cellulose, especially when modified by toasting to

show that the changes occurred are not

adjust its colour, is unknown. Obviously, this toasting gives room for some chemical

significant enough to prevent its use in

changes, that’s why conservators should look for possible caveats of its use. To

paper conservation.

Prepare a diluted mixture of

damages, but several factors might

cellulosic hydrolysis processes that

exposing the samples to a Light

cellulose is used in paper conservation

carried out with a Portable Spectro-

powdered cellulose and adhesive

interact in each context, and it is

wouldn’t take place in dry conditions

Emitting Plasma (LEP) source. LEP

mostly as filler, or as a covering


that will be sprayed in order to

complex to isolate them and expect

(unlike reality)

. Looking for this

is a full spectrum light source that

material, rather than a structure

Minolta. The obtained data was

obtain very thin films [5].

that the overall behaviour shall be

similarity to reality the reference

replicates sun light almost identically,

provider. The possible change on the

recorded in CIE L*a*b coordinates,

the same by just summing up those

ageing of 70ºC, at 70% HR for 15

with an intensity of 52,569 lux.

mechanical endurance after ageing

where L represents lightness, “a”

separate factors .

days was chosen.

would have a minor impact in terms

corresponds to redness-greenness,

of the conservation treatment.

and “b” to blueness-yellowness. The

For this study, the samples were


The samples were exposed during



prepared by spraying a mixture

Even if far from reality, these tests

As for the protocols regarding light

188 hours, with a distance of 25 cm

of water, adhesive and powdered

provide a general idea of material

damage, the reference was the ASTM

between light source and sampled



performance that is very useful,

D6789-02 Standard Test Method for

material. Under these conditions a total



evaluated with euclidean values (DL,

terephthalate sheets. This material

particularly for new materials with

Accelerated Light Ageing of Printing

exposure of 39,690 watts was achieved

because they can alter the support’s

Da and Db respectively, and DE as the

was chosen because it is chemically

somewhat unexpected behaviour.

and Writing Paper by Xenon-Arc

(almost like the standard, if it wasn’t for

chemical context if they prove to

overall change) [10].

Exposure Apparatus

. According

4 extra hours of exposure). No filter

be meaningful enough. The study of

tests selected in this study in order

to it, samples should be exposed

was applied in this case, thinking that

chemical changes has consisted of pH



for 48 hours under an 800 watt/m2

radiation under 320 nm would not

measurements and the identification,


microcrystalline cellulose consisted in:

light source which has been filtered

make relevant changes for this purpose

if present, of reducing sugars.

isinglass, at the concentration of 1.5%;

1. Long exposure to controlled high

to eliminate radiation under 320 nm.

(visible range of wavelength).

5.0% and 1.5% in water respectively.

temperature at a stable relative

This represents a total amount of

Proportions of adhesive/water were


38,400 Watts exposure.


The artificially induced degradation

inert and dimensionally stable. Three different mediums (synthetic and






established in relation with their individual adhesive strengths. As for powdered cellulose, four different tones were used: raw (white)





2. Long exposure to a full spectrum light source. -dents.




pHmeter.As expected, ageing involved


possible regarding discolouration and

an acidification of the samples.

fading, hence the importance of this


photochemical, chemical and physical.

different degrees, the three of them

in four pieces. One was kept as a

relative humidity was performed in

factors such as discolouration, acidity

rinsed twice in tap water (pH 7.14).

control and the other three were

a Boekel Scientific incubator. The

or mechanical endurance, for instance.

All in all, 12 different samples (four

exposed to ageing as detailed above.

samples were exposed during 15

The latter has not been examined

types of cellulose, applied with 3

Literature offers a wide choice of

days to a continuous temperature

in the present study for two main

different mediums), plus Whatman

artificially induced ageing tests, each

of 70º C with the relative humidity

reasons: first because the shortness

filter paper, are being studied.

of them focused on specific issues

conditioned to 70%.

of the fibres (22 microns) would give

protocol to follow [7][8].




tests intend to accelerate particular

because this fibre length prevents any

exposure, the presence of a certain

discolouration, bleaching…). Artificial

attempt to obtain tissues of significant


ageing with light was attained by

structural function; actually micro-

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with both light and heat, were the most

Table 1 • pH (average per toasting degree)

secondly, and as a result from the first,



The analysis for colour changes was

than the heat ageing; and samples aged

tests, such as folding endurance. And

3.2. Light

Light can cause a variety of effects

When it comes to high temperature


Light ageing acidified cellulose more

no relevant values with the typical



the paper (or cellulose) condition.

used are intended to be as stable as

These changes might show in diverse

materials, and yet there is no unique

pH variation is a good indicator of


controlled high temperature at a stable


4.1. Chemical changes: pH variation

an XS series 8 ver1.0 01/25 surface

Each prepared sample was divided



terms of inpainting since the materials

cellulose; and toasted cellulose in 3



corresponding changes have been

The measurements were taken with

Degradation occurs in several levels:

a stable relative humidity

On the other hand, chemical

Colour changes are the main issue in

3.1. Controlled high temperature at

3. Combination of the two prece-







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Table 3 • Benedict’s test results SAMPLE

















gr SolkaFloc






general, raw cellulose. The lower slope

gr Benedict







of its curve (pale blue) compared to













acidic. Acidification has affected less, in

the rest, indicates that no toasting makes cellulose more reluctant to

500 -1000


reagent made it difficult to determine whether the second had suffered some discolouration or not. To prevent the visual contamination


of the reagent’s response, the cellulose

suffer acidification after ageing, when compared to toasted samples.

samples were wrapped in filter paper, process, the expected outcome is a

Table 2 • Acidificaation rate (ph units) after ageing

Looking at non aged samples (first column in table 1) slightly and

rinsing had not been checked, but

see table 1, 4th column), increasing

medium toasted samples (yellow

it seems likely that the acidification

accordingly to the toasting degree

and orange, respectively) show an

after this toasting was somehow

(major toasting implies a more acidic

unexpected increase of pH compared

counteracted, or even surpassed, by

outcome, table 2). Back to table 1,

to raw cellulose, and only the most

the alkalinisation of the rinsing water

medium toasted samples (yellow

toasted hue results (in brown) were

(at a pH of 7.14).

and orange) are still, overall, slightly

more acidic than raw cellulose.

In order to analyse acidification

less acidic than untoasted samples.

This difference shortens along the

despite the possible interference

However, the tendency seems to

following ageing stages (2nd to 4th

of tap water, let’s observe a table

indicate that they would at some

columns). A possible explanation to

considering the decrease of pH units

point reach the same level and

this anomaly is the fact that toasted

along the different ageing stages

surpass it, for they have the highest

samples were rinsed twice in tap

(table 2).

rate of acidification (see in table

(slightly alkaline) water. pH before

It can be stated that heat ageing

2: a major decrease of 1.44 units;

(first group) is the least acidifying.

compared to the maximum decrease

And, again, the possible interference

of raw cellulose: 0.86; and besides the

of tap water alkalinisation is more

starting point is higher too: 7.6).

evident among the toasting degrees within this 1st group. Raw cellulose has proved to keep its pH more stable than the toasted

Figure 2 • F rom left to right, samples 1 to 5 (and at the very left the one containing glucose) soaked in Benedict and after boiling them for several minutes. Only cellulose #5 gives a positive result (greenish), beside the full positive in an orange-red tone: pure glucose (right).


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certain amount of glucose monomers or other carbohydrates formed by glucose (such as cellobiose). In order to detect the presence of this monomer Benedict’s analysis has been performed, which gives positive results for reducing sugars. Reducing sugars bear a free aldehyde (-CHO) or ketonic (-CO) group in opposition to non reducing sugars, that lack these free groups in their molecules. Reducing sugars include all monosaccharides (i.e. glucose) and many disaccharides (such as cellobiose, which is formed by two glucose monomers). Cellulose is a non reducing sugar. Benedict’s analysis is not quantitative,

4.2. Benedict’s analysis for reducing

but qualitative. Nevertheless, the visual


result indicates a range of magnitude,





samples in the 2nd (light) and 3rd

which is most useful for this purpose.

specifically a homo polysaccharide,

groups (light & heat aged). In the

A negative result implies no colour

because it is formed by a long chain

combination of both light and heat

change (the reagent should remain

of a unique monomer: glucose. The

ageing, almost all toasted samples

pale blue), whereas positive results go

degradation of cellulose might involve

turned out to be more acidic

from green, yellow, orange and brick-

the breakdown of this long chain into

than untoasted cellulose (with the

red. The amount of reducing sugars

its smaller constituents. Therefore

exception of sample #2, yellow,

according to colour should be in

at some stage of this degradation

these shifts: greenish (500-1000 mg/

dL glucose), yellow (1000-1500 mg/

and the cluster was soaked in the reagent,

dL), orange (1500-2000 mg/dL) and

allowing it to react, yet not permitting

full positive is red or brick red (>2000

the cellulose to disperse in the liquid.

mg/dL). A negative result implies that

The results prove that there is no

the amount of by-products should be

significant amount of glucose (or any

none or not higher than 500 mg/dL.

other form of reducing sugar, such as





cellobiose) in samples 1 to 4. They all

consisted in analysing 5 different Solka-

kept the reagent unchanged in colour.

Floc © samples with Benedict’s reagent:

As for the fifth (most toasted and non-rinsed Solka-Floc ®) it shifted

1. Untreated.

to a greenish hue, meaning that the

2. Toasted and rinsed twice in tap

content of reducing sugars should be

water. 3.  Further toasted, rinsed twice in tap water. 4.  Further toasted, rinsed twice in tap water. 5.Further toasted, unrinsed.

not higher than 1000 mg/dL. This outcome should not be surprising, because it is known that cellulose is an extremely difficult polysaccharide to break down [11] (human digestive system cannot do it either) and extreme conditions are required to do so

A sixth sample of pure glucose was

(chemically, at high temperature, greater

added in order to have a positive

than 300 ºC, and high pressure, about

result to compare with, and to know

25 MPa, or alternatively, enzymatically

the boiling time needed to obtain a

with cellulases).

reliable positive result (shifting colour occurs only after some boiling).

The conclusion extracted from these results is that the breaking

While checking the visual results,

down of cellulose even after a high

specially toasted samples (2-5) arise the

degree of toasting (sample #5 is dark

problem that the brownish hue of the

brown) scarcely jeopardizes the main

toasted cellulose mixed with the blue

chain. The by-products derived from

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Being the case that some colour fading

this toasting are water soluble and

occurs, it might be easily corrected by the

very easily removed with a simple

addition of some colouring (watercolour,

rinsing, or two for more assuredness, in order to avoid any interaction of these by-products with the original support. In summary, toasted and

 ntoasted SolkaFloc (sample #1) prepared with isinglass at different ageing stages. Lower Figure 4 • U values involve darker colours. The major change occurs in the blueish wavelength (meaning there is a yellowing/bleaching).

rinsed cellulose has no crucial by-

stored artwork or even exhibitions.

products derived from the breakdown

An exposure of 188 hours at 52,569

of the polysaccharide that can be an

lux means almost 10 million lux hours

issue for conservation treatments or

(9,882,972 lux hours) which is like 392

the treated objects.

times an average exhibition of 25,200 lux hours (50 lux 7 hours a day, 6 days

4.3 Colour Changes

Colour changes in light aged samples

per week during 12 weeks). The results might seem anyway

have quite dramatic results, with




evident bleaching of the toasted

accelerated ageing induced by heat


involved a slight darkening (not

In order to evaluate the tests

perceptible by the naked eye for the

fairly it must be highlighted that this

less toasted samples, and scarcely

particular light ageing is far from

perceptible for the more toasted

being a real situation, and it would

ones), whereas light ageing implied a

never occur in normal conditions on

notorious bleaching.

Figure 3 • 3 rd toasting degree samples. Rows from top to bottom: both aging methods, light ageing, heat ageing, not aged. Columns from left to right: Aquazol medium, methyl cellulose, isinglass.

Samples with both ageing processes

Whatman paper has a model

in general terms it can be stated that

were even more faded than those

behaviour at any ageing stage, with

no toasting involves an acceptable

exposed only to light. Although the

imperceptible DL (: -0.19; : 0.07

discolouration at any ageing stage

difference within these two is not

and : -0.02) and just noticeable DE

(DE<1.78 in the worst case). Further

remarkable, it can be striking that heat

change at any stage (: 0.73; : 0.91


ageing darkens, light ageing causes

and : 0.93).

where some of the light and medium



Heat ageing involved some yellowing

toasted samples can be found still

both -heat and light aging- fade even

in all the samples (Db>0), whereas light

in the acceptable change range, yet

more than the latter, not something

ageing and both ageing methods implied

noticeable (maximum values are for

in between. It seems like already

the contrary (negative Db, meaning

#4 toasting, for both methyl cellulose

damaged fibres are more sensitive to

some blueing, or less yellowing).

and isinglass, with DE around 3.0).

discolouration than fibres in better

The observation of Da values (red/

Heat ageing is the least damaging,

condition (let it be noted that heat

green colour) is related to the variation

whereas both heat and light ageing

ageing was done prior to light ageing in

of the toasting hue. Their values are

have the worst results.

the samples aged with both processes).

much smaller than Db, and they do

Most of the samples with major

Figures 4 and 5 correspond to the

not provide relevant information to

unacceptable colour change fall into

evolution on isinglass samples along

this study, or it is difficult to say, since

light ageing and both ageings (#4

ageing and toasting, which is similar in the

variations do not have such a direct

isinglass, #2 MC and #3 Aquazol

other two mediums. In all of the samples

relationship to ageing, like Db.

provide the maximum rates, all of

more toasted the samples are.

As for mediums, their behaviour is quite similar. Methyl cellulose (MC)

them at light or heat & light ageing: DE= 25, 26 and 27 respectively).

However, the main visual change

has the best performance in terms of

When placing into context the values

turned out to be fading and not

stability, and Aquazol® goes last. But

(being aware that the light exposure

yellowing or darkening as expected.

we cannot judge the latter in equal

ageing was unfiltered, unlike most cases

conditions to isinglass and MC, because

in reality) it can be concluded that the

it had a concentration 3 times bigger.

results are convenient for the case of

Analysing the obtained values of CIE L*a*b it can be stated whether

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a strong lightening/brightening, and

light bleaching is more noticeable the


Figure 5 • T  oasted SolkaFloc (sample #4) prepared with isinglass. The target (in red) is now darker compared to untoasted cellulose (previous image). Difference between ageing stages are bigger too. #2 and #3 have curves accordingly to this evolution.

the colour change is imperceptible

When considering the total amount

inpainting as long as some precautions

(DE<0.5), noticeable (0.5<DE<1.6) or

of change (DE) it is still complex to

are taken into account (rinsing and

unacceptable (DE>3.2)

see a straight forward relationship, but

using only slightly toasted cellulose).



pastel, or whichever technique suits for each particular case). And secondly but not less important, fading will never be perceived as a stain, unlike situations in which darkening happens. Also, In terms of criteria it is accepted that inpaintings be slightly paler than the original surrounding paint, so, unless the fading is very pronounced, it might not always be necessary to re-match a faded inpainting. And last, but not least, a filling with microcrystalline cellulose will not become darker than the original, as long as the initial filling wasn’t. 5. CONCLUSIONS Chemical changes after ageing in the tested material are minor and should not discourage its use, as long as a proper rinsing is made. The breaking down of the cellulose chain even after a high degree of toasting is negligible, and a slight decrease in the pH can be easily corrected with the addition of a base such as calcium hydroxide. In relation to discolouration it is good to know that shifting occurs in a way ­ – fading – which is not perceived as a stain. In the worst case of bleaching the cellulose inpainting can be easily adjusted, if necessary,

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with proofreading and editing this article.

without replacing the whole infill. However, it would be a smart precaution to prevent this undesired effect at any rate on the long term by using only slightly toasted hues, and adjust the darkest colours by other means, either adding pigments or dyeing raw cellulose. Ageing tests are thought to reveal unknown






the them


previously to match the desired data.

[1] FUTEMICK, Robert et al. 1987 Filling

Photochemical and Thermal Aspects. BERLAND,

Further studies should be made to

Losses. Chap. 26 in Paper Conservation

Dinah, ed. – Research in Conservation, 4. USA:

obtain more specific results. Chemical


degradation study could be improved with viscosity analysis (not possible with the present samples because of their low weight); pH measurements following the Tappi standard (cold or hot extraction), and light ageing at shorter exposure with the appropriate filter.




Institute for Conservation Book and Paper Group



08/08/2017) [2] SCHENCK, Kimberly et al. 1994 Inpainting. Chap. 30 in Paper Conservation Washington





providing most useful resources for analysis



pHmeter). Special thanks to Ricardo Ruiz, Maite Toneu and Ruth Sadurní. Dr. Ainhoa Nieto (Scripps Research Institute) for her help with the heat ageing chamber. J. Jerónimo Perez-Escolano for his help


Nome artigo

46 [8] PORCK, Henk J. – Rate of Paper Degradation. The Predictive Value of Artificial

Institute for Conservation Book and Paper

AgingTests. Amsterdam: European Commission


on Preservation and Access, 2000.



[9] Standard Test Method for Accelerated

on Paper. London: Archetype, 2008.


[7] GARCÍA HORTAL, José Antonio – Fibras



[3] POULSON, Tina Grette - Retouching Art

Centre de Restauració de Béns

115. papeleras. Barcelona: Ediciones UPC, 2007. pp.



The Getty Conservation Institute, 1994, pp.

Xenon-Arc Exposure Apparatus ASTM D6789-

[4] BERNSTEIN, James; EVANS, Debra – Cellulose powder for fills and compensation. In Mastering Inpainting. FAIC workshop manual. San Francisco, CA. 2010. [5]


Light Aging of Printing and Writing Paper by 02 (2007). West Conshohocken, PA: ASTM International, 2007 (withdrawn 2011). [10] MICHALSKY, Stefan; DIGNARD, Carole – Ultrasonic misting. Part 1: Experiments on



appearance change and improvement in

Stephanie – Two New Techniques for Loss

bonding. JAIC. Vol. 36, nº2 (1997) pp. 109-126.

Compensation in Art on Paper: Integration

[11] JIN, Xi – Breaking Down Cellulose.

of Surface Losses Using Textile Fibers and the

In the course Physics 240: Introduction to

Use of Sprayed Cellulose Powder to Minimize

the Physics of Energy. Stanford University,

Foxing and Other Discoloration. The Book and

November, 2010.

Paper Group Annual. Nº 32 (2013), pp. 52. [6] FELLER, Robert L. – Accelerated Aging:

https://goo.gl/Kb5kUi (accessed 05/25/2017) Postprints Nome artigo




Aquazol® 500; Retouching colours; Watercolours;

of all water-sensitive surfaces such


as contemporary artworks, can be

1. U  niversity of Urbino Carlo Bo, Department of Pure and Applied Sciences, Conservation and Restoration of Cultural Heritage;Via Aurelio Saffi 2, 61029 Urbino (PU), Italy: vanessa.ubaldi@hotmail.it; daphne.deluca@uniurb.it; roberto.franchi@uniurb.it 2. University of Delaware, Department of Art Conservation; 303 Old College, Newark, DE 19716, USA: doczepp@gmail.com 3. Association CESMAR7, Centre for the Study of Materials for Restoration;Viale Dei Mille 32, 42121 Reggio Emilia (RE), Italy: conservazioneres@tiscali.it 4. U  niversity of Parma, Department of Mathematical, Physical and Computer Sciences; Parco Area delle Scienze 7/A, 43124 Parma (PR), Italy: pierpaolo.lottici@unipr.it 5. U  niversity of Pisa - Department of Chemistry and Industrial Chemistry;Via Giuseppe Moruzzi 13, 56124, Pisa (PI), Italy: francesca.modugno@unipi.it 6. Applied and Laser Spectroscopy Laboratory, Institute of Chemistry of Organometallic Compounds, Research Area of National Research Council(CNR);Via G. Moruzzi, 1 – 56124, Pisa (PI), Italia: egrifoni@hotmail.com



has lead to this new formulation of


retouching colours is the fact that the composition of watercolours that are found on the market today, and that are used in the conservation


field, is not always known. In fact, the The research consists of proposing a new material to be used for the

Vanessa Ubaldi (1) | Roberto Bestetti (3) | Roberto Franchi (1) | Emanuela Grifoni (6) | Pier Paolo Lottici (4) | Francesca Modugno (5) | Richard Wolbers (2) | Daphne De Luca(1)

overcome. Another

Artificial aging;

preparation of retouching colours for the retouching of artistic artefacts, experimenting



colours to the common watercolours which are found on the market today, usually used for pictorial retouching of artworks

. These colours differ


from the traditional Arabic gum based watercolours precisely for the use of a new synthetic binder: Aquazol® 500. This polymer has good



and a wide spectrum of solubility in

various organic polar solvents, with

manufacturing firms usually indicate

relatively low toxicity, which make it an

only in general terms the composition

extremely versatile material especially

of the colours sold, to protect patents.

when used as a binder for retouching

Unfortunately, the lack of precise

colours. Its positive characteristics and

information and the substitution or

above all, its peculiarity of being soluble

variation of the ingredients in the

in many solvents, not only in water [6-

composition of commercial colours

8], enable us to produce colours that

means that in these colours there

can be used for the retouching of

may be substances which are unstable

any type of artistic artefact, including

over time, of which the restorer is

those that are water sensitive. In

unaware.These are the main causes of

this way, a limitation of the usual

chromatic alterations that commercial

watercolours made of gum Arabic,

watercolours show. Moreover, the

which are soluble solely in water and

colours that we find on the market are

cannot be used for the retouching

made with a precise balance between


all their ingredients, and they cannot be changed, but if restorers are able

In this research project we propose a new material usable for the preparation of

The results obtained from the study of the self-produced colours were then

to self-produce colours for pictorial

retouching colours as an alternative to the more common watercolours normally

compared with those obtained from the same scientific investigations carried

retouching, then they can change this

used for the pictorial restoration of the artworks. Compared to traditional Arabic

out on the only commercial watercolours based on Aquazol® currently on the

gum based watercolours, the self-produced colours here presented are made with

balance according to their own needs,

market: QoR® by Golden Artist Colors (USA).

a new synthetic binder: Aquazol® 500. This polymer has good physical-chemical

The results obtained from the study demonstrate that, thanks to its extreme

and decide on the composition of the

properties and a wide spectrum of solubility in various organic polar solvents,

stability, Aquazol® 500 can be considered a valid binder for retouching

which also makes it suitable for the retouching of water sensitive artworks. These

colours. In fact, the polymer does not degrade and does not show cross-

new retouching colours with Aquazol® 500, prepared with two different recipes,

linking phenomena. The self-produced colours are confirmed to be much

were investigated with different scientific analyses both before and after artificial

more stable over time and therefore much more suitable than the QoR®

aging in a Solar Box, in order to evaluate their stability over time.

watercolours for pictorial retouching of artistic artefacts.

colours to use. For these reasons, and especially because the colours used for pictorial retouching, like all materials used for restoration, must be stable and reversible over time, it was

Recipe A: composed of Aquazol®

The results obtained from the study of

formulation of retouching colours. In

500 dissolved in demineralized

the colours produced with these two

this way, when restorers self-produce

water, pigments, glycerin, xanthan

Recipes A and B were then compared

colours using known ingredients,

gum and 2-phenoxyethanol;

with those obtained from the same

Recipe B: composed of Aquazol®

scientific investigation carried out on

composition and characteristics are

500 dissolved in demineralised water,

the only commercial watercolours

known, because they have been

pigments and 2-phenoxyethanol.

based on Aquazol® currently on the

decided to experiment with this new








with the artificial aging of the samples.

The xanthan gum was purchased from






Saponaria, cosmetica consapevole”

colours to avoid the formation of microorganisms and in particular, moulds.

that sells raw materials for the personal


Pigments: a limited number of


inorganic and organic pigments were

The materials used for preparing the

cosmetics. This gum was chosen

selected to be added to the binder

self-produced colours were as following:

because usually gum used in the

prepared with Recipes A and B.Taking

Binder: Aquazol® 500, sold by

cosmetics field for the preparation of

as reference the twelve colours used

2.1 Materials Used


tested and studied especially for this

The two recipes differ only in

market: QoR®. These watercolours

aim, they can be sure they are using

the addition of the two additives

were introduced on the market in May

Kremer Pigmente GmbH & Co. KG.;

creams has a clear grade, an essential

to perform pictorial retouching from

colours which are stable and durable

introduced in Recipe A: glycerine and

2014 by Golden Artist Colors (USA),

of the four existing molecular weights,

feature to consider when choosing

the high school of Rome, the Institute

over time, something not guaranteed

xanthan gum.The idea of ​​making these

the company that today produces and

it was chosen because it is composed

this material. In fact, a gum with a

for Conservation and Restoration

by commercial colours.

two recipes was inspired by the studies

distributes these only in the United

of larger molecules which remain

yellowish colour could alter the tone

(ISCR), ten pigments were selected

The aim of the research was to

conducted by R. Wolbers, who was

States. They were included in the

on the surface to which it is applied

of the prepared colours, and for this

in total, seven inorganic and three

create self-produced colours based

the first to use Aquazol® as a pigment

study for two reasons. Firstly, because

and do not penetrate the substrate,

reason, is not recommended. The

synthetic organic purchased from

on Aquazol® 500, characterizing the

binder . He suggested adding xanthan

they are based on Aquazol®, it is

a feature that a retouching colour

glycerol was purchased by Kremer

two different companies: an Italian

materials that make these and analysing

gum to the colour preparation recipe,

important to make a comparison with

should have in view of its future

Pigmente GmbH & Co. KG.

company of Verona, Dolci Colori Srl,

the chemical-physical characteristics

which helps pigment dispersion in the

self-produced colours that are made


of the colour samples before and

binder, and glycerin, which improves

with the same binder. The second

after artificial ageing in a Solar Box,

the workability of the colours.Wolbers

reason is that the ingredients used to

to evaluate their stability over time.

argues that to create a uniform and

prepare the QoR® are not known,

To characterize the materials used to

homogeneous colour, it is necessary to

because the manufacturer does not

prepare the colours and to identify

add a substance to help the dispersing

specify the components present in the

possible interactions between the

of the pigment, because it is possible

colours and does not even indicate

binder and the pigments combined

that Aquazol® alone cannot disperse

which of the four molecular weights

with it, different scientific analyses

it completely, creating lumpy and

of Aquazol® was used to make them.

were used, chosen considering the



For these reasons, the self-produced

substances to be analysed and the

over time, can undergo chromatic

colours with the two Recipes A and

information to be obtained. These



B were compared to the commercial

were also used to observe any

of the pictorial film, or in the worst

colours QoR® to discover if there are

differences between the two recipes

cases, the separation of the binder

differences and similarities between

used to prepare the self-produced

from the pigments. The comparison

these two types of colours and to

colours and to understand which of

of these two recipes was investigated

understand which are the best ones

the two is the best one to use for

to discover if the addition of these

to use for pictorial retouching of

the preparation of colours based on

additives would affect workability and

artworks, considering the stability and

Aquazol® 500. The recipes used are:

especially colour stability over time.

durability parameters over time, tested




Vanessa Ubaldi | Roberto Bestetti | Roberto Franchi | Emanuela Grifoni | Pier Paolo Lottici | Francesca Modugno | Richard Wolbers | Daphne De Luca


which provided the seven inorganic

purchased from Sigma-Aldrich S.r.l..

pigments (Table 1), and a German

This preservative was added to

company, Kremer Pigmente GmbH

Additives: xanthan gum and glycerin

(glycerol), present only in Recipe A.


Table 1 • Seven inorganic pigments




Dolci Colori

Titanium White 7525/1

Dolci Colori




Pigment White 6


Pure Ultramarine Blue


Pigment Blue 29


Dolci Colori

Cadmium Red Medium 3540


Pigment Red 108


Dolci Colori

Ocher icles Lemon


Pigment Yellow 43


Dolci Colori

Green Chromium Oxide Hydrate


Pigment Green 18


Dolci Colori

Burnt Sienna TOR/SA


Pigment Brown 7


Dolci Colori

Ivory Black


Pigment Black 9


The use of Aquazol® 500 as a binder for retouching colours: analytical investigations and experiments


& Co. KG, which provided the three

retouching, and if alizarin was found

was the Colour Index ™ Generic

organic pigments (Table 2).

to be unstable, then if one substitute

Name, which describes a commercial

was better than the other.

product for its specific use class, its











to the ten pigments used to prepare

Golden Artist Colors

Permanent Alizarin Crimson


Pigment Red 177

self-produced colours.

Golden Artist Colors

Pyrrole Red Deep


Pigment Red 264

Golden Artist Colors

Quinacridone Red


Pigment Violet 19

Kremer Pigmente

Alizarine Crimson Dark


Pigment Red 83


Kremer Pigmente

Irgazine® Ruby DPP TR


Pigment Red 264


Kremer Pigmente

Quindo® Pink D


pigments are not present in the

Pigment Violet 19

The proportions of the ingredients used to prepare the colours with the two Recipes A and B were chosen taking into consideration the


material and guidelines provided by Professor Richard Wolbers during


colours used by the ISCR and are

-Aquazol® watercolours,


usually excluded from the restorer’s

QoR®, seven inorganic (Table 3)

palette because they are considered unstable over time and therefore not suitable for pictorial retouching. Based on these considerations, it was decided to include these in the study, to investigate their stability when

2.2 Preparation of the samples


the Workshop on Aquazol® in Turin



RECIPES A AND B: five different

characteristics and those composed

parameter, Critical Pigment Volume

Out of the five solutions prepared

Table 5 • Recipe A: Preparation of the five solutions of Aquazol® 500

2° Category


been selected to compare with self-

of pigments into five categories and


3° Category


produced colours. The parameter

for each of these, has identified the


4° Category


used to choose the ten QoR®

right percentage of binder to be


5° Category





4 drops in a solution of

0,04 gr in a solution of 100 ml

4 drops in a solution of 100 ml

100 ml

Table 3 • Seven inorganic QoR® Table 6 • Recipe B: Preparation of the five solutions of Aquazol® 500 COLOR INDEX INTERNATIONAL PREPARED SOLUTIONS




1° Category



2° Category


Pigment Blue 29


3° Category



Pigment Red 108


4° Category


Yellow Ochre (Natural)


Pigment Yellow 43


5° Category


Golden Artist Colors

Viridian Green


Pigment Green 18

Golden Artist Colors

Burnt Sienna (Natural)


Pigment Brown 7

Golden Artist Colors

Ivory Black


Pigment Black 9

Golden Artist Colors

Titanium White


Pigment White 6

two substitutes: Irgazine® Ruby DPP

Golden Artist Colors

Ultramarine Blue


TR can be considered an excellent

Golden Artist Colors

Cadmium Red Medium

Golden Artist Colors

could both be used for pictorial


Recipe B (Table 6).


Alizarine Crimson Dark, as well as

discover whether the alternatives


categories is based on the CPVC

Wolbers has divided different types

to test the stability and durability of

to light alizarin. The objective was to


colour. Pigments with the same

and three organic (Table 4) have


Quindo® Pink D is a valid alternative


Recipe A (Table 5) and five with



substitute for dark alizarin, while

up the pigment powder (Table 7).

to be added to the five pigment

1° Category


pictorial retouching, it was decided

characteristics of the grains that make

create a homogeneous and uniform


and the indications and


binder solutions were prepared with

advice that the Professor provided.

in 2014



choice of the percentage of binder




combined with pigment powder to






exposed to accelerated aging. Since alizarin is a very useful colour for


be added to the binder, considering



tonality, and a serial number, referring

Table 2 • Three organic synthetic pigments

Table 4 • Three organic QoR®


Vanessa Ubaldi | Roberto Bestetti | Roberto Franchi | Emanuela Grifoni | Pier Paolo Lottici | Francesca Modugno | Richard Wolbers | Daphne De Luca






grouped into a single category. The


4 drops in a solution of 100 ml

Concentration[11], which identifies the

with Recipes A and B, only one

optimum concentration of pigment to

was selected, the one with the

The use of Aquazol® 500 as a binder for retouching colours: analytical investigations and experiments


20% Aquazol® 500 prepared with

A and B with the ten selected pigments,

The colours were prepared by

3. THIRD PHASE- Preparation of

The experimentation is structured

by Raman Spectroscopy, to obtain as

both recipes. This was applied on a

divided into the five categories

mixing together the right amount

commercial watercolours QoR®:

in different phases that can be

much information as possible on the

microscope slide to then undergo

identified by Wolbers (Table 7: the

of binder and pigment and were

these are sold in tubes that are ready

summarized as follows:

composition of the pigments used to

scientific investigation.

ten pigments used, corresponding to

worked with a glass pestle to

for use. They were only diluted with

2. SECOND PHASE - Preparation

the pigments subdivided by Wolbers

obtain a homogeneous compound

demineralized water and applied on

of the self-produced colours with

into the five categories, are highlighted

without clumps. Subsequently they

microscope slides to then undergo to

Recipes A and B: The self-produced

with the same colour). Twenty colours

were applied on the microscope

scientific investigations.

colours were obtained by mixing the

were prepared: ten with Recipe A and

slides before undergoing scientific

binder solutions prepared with Recipes

ten with Recipe B.


2.3 Scientifics Investigations

1. Study of inorganic and organic pigments;


1° Category

2° Category

Phthalocyanines Red Quinacridones Dioxazine Violet Alizarin Crimson Prussian Blue Carbon Black Red Iron Oxides (uncalcinated) Zinc White Titanium White Yellow Quinacridones, Benzimidazolones Synthetic organic pigments


Quindo® Pink D - 23402

Titanium White 7525/1-PB/0241 Alizarine Crimson Dark - 23610 Irgazine® Ruby DPP - TR - 23182

granular form and in solution at 20%

values for each colour and for binder

prepared with Recipes A and B;

solutions, to highlight any changes due

3. Study of additives: xanthan gum



Aquazol® at 40% in solution (Recipes A e B)

Aquazol® at 35% in solution (Recipes A e B)

Ocher icles lemon TR/0324 Green Chromium oxide hydrate PA/0601 Pure ultramarine blue PA/0561

4° Category

Cadmium Yellow Cobalt Violet Red and Yellow Iron Oxides (calcined)

Ivory Black PA/0597 Burnt Sienna TOR/SA-TR/0262

5° Category

Cadmium Orange Cadmium Red Manganese Violet, Manganese Blue

Cadmium red medium 3540 - PA/0554



Aquazol® at 30% in solution (Recipes A e B)

Aquazol® at 25% in solution (Recipes A e B)

Vanessa Ubaldi | Roberto Bestetti | Roberto Franchi | Emanuela Grifoni | Pier Paolo Lottici | Francesca Modugno | Richard Wolbers | Daphne De Luca

Aquazol® at 20% in solution (Recipes A e B)



spectroscopy: pigments,



and additives and observe if the

and B;

self-produced colours and QoR®

5. Study of commercial watercolours based on Aquazol®: QoR®;

analysed before and after aging presented any changes. Through

6. Comparison between QoR® and

this technique it was also desired to

self-produced colours with Recipes A

assess whether the pigments mixed

and B.

with Aquazol® 500 can interact with

For each phase, different scientific

it, and if the pigments present in the

investigations were used, aimed at

self-produced colours are the same

characterizing and studying Aquazol®

used in the preparation of QoR®;

based colours and the materials

Attenuated total reflectance-Fourier

that compose them. The scientific



investigations used were as follows:



Stereo Microscope: to obtain


Chromatography/Mass Spectrometry


(Py-GC/MS): to obtain qualitative

samples colours before and after

information on the organic pigments,

artificial aging, to see any changes on

the binder,

the surface of the colours, such as

also used to obtain information about

craquelures and lifting paint;

the binder solutions, the organic self-



and additives. This was

X-ray Diffractometer (XRD): to

produced colours and on equivalent

have information on the crystalline

QoR®, before and after aging, for two

phases present in the analysed

reasons. Firstly, to discover if there are

inorganic pigments and to make a

differences in ATR-FT-IR spectra caused

comparison with the data obtained

by deterioration processes: such as


to artificial aging;

based on Aquazol® 500: Recipes A

Yellow Iron Oxide Viridian Ultramarine blue Ultramarine violet Cobalt Pigments (blue, cerulean, turquoise, green)

3° Category




investigation: to

identify the relevant colorimetric

4. Study of self-produced colours



2. Study of binder: Aquazol® 500

and glycerin; Table 7 • Preparation of the twenty self-produced colours: Recipes A and B

prepare the self-produce colours;

The use of aquazol® 500 as a binder for retouching colours: analytical investigations and experiments


the formation of oxidation processes









quadrupole time-of-flight (HPLC-

the chromatographic profile of the

ESI-Q-TOF): to characterise the

samples that could indicate the cross-

QoR® Permanent Alizarin Crimson

linking phenomena of the polymer;

which during the experimentation to

showed a different composition from


the corresponding Alizarine Crimson

properties of the solid binder and the

Dark pigment used to prepare the

organic pigments. This was also used

homonymous self-produced colour

to analyse, before and after aging, the

with Recipes A and B;





samples of the binder in solutions and




only one of the organic self-produced

Spectroscopy (LIBS): to characterise

colours, the Irgazine® Ruby DPP-TR,

the possible presence of inorganic

and the equivalent QoR®, Pyrrole


Red Deep, to observe the potential

agents in the organic pigments

changes of temperature of the thermal

and in the un-aged organic QoR®.

degradation of the mixtures of colour

In fact, it is noted that organic






pigments, being





chromatography with diode-array

nor natural substances, are fixed

detection (HPLC-DAD): to obtain

on semi-transparent inert matrices

qualitative information on two organic

of inorganic origin, usually made of

pigments, Alizarine Crimson Dark and

hydrated oxide of aluminium, to

Quindo® Pink D to compare with

become insoluble pigments in the

those obtained from the study of

medium in which they are dispersed;

the two homonymous organic self-

Artificial aging: the samples were

produced colours with the Recipes

subjected to artificial aging in Solar

A and B, and the two corresponding

Box with irradiation in the visible

organic QoR®, Permanent Alizarin

spectrum to check their stability over

Crimson and Red Quinacridone, in

time. Indoor aging was simulated,

order to assess whether the pigments

and the samples were subjected to

used in the QoR® are effectively the

just one cycle of aging with a total

same as those used for the preparation

radiation exposure of 777 hours with

of self-produced colours

a light intensity equivalent to 1181 MJ/





m. 2



Secondly, to observe any changes in







characterization of the inorganic pigments analyzed in XRD and Raman Spectroscopy showed that the chemical composition of the pigments indicated in the technical and safety data sheet is not always fully accurate. In fact, the following pigments have shown the presence of undeclared substances:

The experimentation conducted

the binder, giving rise to the formation

alters less than that prepared with

on Aquazol® 500 based colours

of new substances, therefore are

Recipe B. Therefore, the use of colour

confirmed the chemical stability of

stable both chemically and physically

prepared with Recipe A is suggested.

the polymer, which can then be used

Even the colorimetric data suggest

In the study carried out on the three

with success as a binder of retouching

that the self-produced colours after

self-produced organic colours, it was

colours. In fact, the results obtained by

aging are stable and do not show

found that Alizarine Crimson Dark

TGA investigation carried out on the



prepared with both Recipes A and B

binder in solution (Recipes A and B)

therefore can be safely used for

tends to darken with time, confirming

indicate that there are no important



the instability of this colour. For this

increases of temperature of polymer

The only inorganic colours that have

reason, its use is not recommended.

degradation as a consequence of aging,

shown evident chromatic changes

The use of the two substitute colours

which means that the polymer neither

after aging are:

tested is suggested because after

chromatic retouching


Pure Ultramarine Blue, prepared

aging they remained stable and did

phenomena. Furthermore, there are

with both Recipes A and B that

not undergo noticeable chromatic

no substantial differences between



variations. As a substitute for light

the binders prepared with Recipes A

reported from the recent scientific

alizarin, Quindo® Pink D can be

and B. For this reason, both can be



used, prepared with both Recipes

Burnt Sienna TOR/SA (TR/0262):

used to prepare the self-produced

. For this reason, it

A and B, whereas as a substitute for

contains calcite, dolomite and anatase


colours, since they are stable and

dark alizarin, Irgazine® Ruby DPP TR

(titanium dioxide), not declared by

would be preferable to find a valid

durable over time and the presence

can be used, prepared with Recipe B,

the company.

substitute, or at least to use the

of the additives does not influence

colour made with Recipe A, which

because it is observed that the one

the chemical-physical characteristics

prepared with Recipe A, although


darkens less than the one prepared

of the polymer. Therefore, it will only

stable, is more subject to chromatic

Spectroscopy, and then in TGA, ATR-

with Recipe B.

be at the discretion of the restorer

FT-IR and LIBS, only two present

to decide which of the two recipes

undeclared inorganic substances:

Recipe B that slightly blackened and

must be used, bearing in mind that

produced colours with QoR® has

Alizarin Crimson Dark: contains

turned yellow, whilst the colour

Recipe A, which differs from B only

highlighted some discrepancies in

titanium (chemical element) which is

prepared with Recipe A did not

for the presence of the two additives,

composition between these two types

not reported on either the technical

change. It is hypothesized that this

produces colours which are easier

of colours and differences in their

data sheet or the safety data sheet of

different response to aging depends

to apply and in which the pigment

behaviour following aging. In fact, after


on the dispersion of the pigment

is better dispersed. After the aging

aging, two organic QOR® have shown

Irgazine® Ruby DPP-TR: contains

in the binder and therefore the

process, the self-produced colours

differences in comparison to the

an inorganic matrix not declared by

one prepared with Recipe A, that

do not show surface morphological

corresponding self-produced colours:

the company, consisting of calcium,

contains xanthan gum which helps

change. Moreover, the pigments which

magnesium and aluminium.

the dispersion of the pigment in the

constitute them, do not interact with

binder, is more homogeneous and

Titanium White 7525 (PB/0241)

and Red Cadmium Medium 3540 (PA/0054): both contain calcite which usually does not characterize these two inorganic pigments; •

Out of the three organic colours, initially



Vanessa Ubaldi | Roberto Bestetti | Roberto Franchi | Emanuela Grifoni | Pier Paolo Lottici | Francesca Modugno | Richard Wolbers | Daphne De Luca

degrades nor shows cross-linking


confirming regarding






variations over time. The







Crimson is made up of a pigment

The use of aquazol® 500 as a binder for retouching colours: analytical investigations and experiments


different to that identified in the

and durable over time. In fact, they

and pictorial layers of the samples

corresponding self-produced colour

undergo more chromatic variations,

prepared in the laboratory, made with



since out of ten QoR® samples, five

different painting techniques.

A and B): QoR® is composed of

darkened and turned yellow as a

The final scope is to create self-

Danilo Bersani and Prof. Claudio


consequence of aging: QoR® Yellow

produced colours with characteristics

Oleari of the University of Parma


Ocher Natural, Ultramarine Blue,



1,2-dihydroxyanthraquinone, present

Viridian Green, Quinacridone Red,

conservation point of view, so that the

Physical and Computer Sciences);

in the corresponding self-produced

and Pyrrole Red Deep have been in

restorer can self-produce stable and

Dr. Jacopo La Nasa, Dr. Sibilla Orsini,


fact altered.

reversible retouching colours with

Dr. Fiammetta Di Marco, Dr. Maria

known composition and chemical-

Rosaria Tinè, Dr. Celia Duce, Dr.

physical characteristics.

Alessio Spepi, Dr. Ilaria Degano




1-amino-9,10-anthraquinone not




QoR® Pyrrole Red Deep shows a

chemical transformation unobserved





The authors acknowledge: Prof.


in the corresponding self-produced colour




(Recipes A and B). It is hypothesized that these differences






and Dr. Francesca Sabatini of the Based on the results obtained,

University of Pisa (Department of

considering the terms of stability and

Chemistry and Industrial Chemistry);

durability over time, one can conclude

Dr. Stefano Legnaioli of the Institute


of Chemistry of Organometallic




stability of QoR® colours. In fact,

are better than the commercial


the colorimetric data indicate that

colours and therefore more suitable

Council (CNR) of Pisa (Applied and

the use of QoR® Pyrrole Red

for pictorial retouching of artistic

Laser Spectroscopy Laboratory); Dr.

Deep and of the other substitute


Valentina Emanuela Selva Bonino of



It would be desirable to continue

the Association CESMAR7 (Center


this research on Aquazol® 500 based

for the Study of Materials for

they undergo obvious chromatic

colours to study in more depth their

Restoration). We are also grateful to

alterations over time. For this

reversibility, and their application on

Prof. Maria Perla Colombini and Dr.

reason, in contrast to organic self-

various types of artefacts, including

Emma Cantisani for having made the

produced colours, it is preferable

contemporary artworks such as

Solar Box available at the Institute for

to use QoR® Permanent Alizarin

alkyd, vinyl, and acrylic paints.

the Conservation and Valorisation

tested, QoR® Quinacridone Red, is



Crimson, which is more stable than

Developing an analytical protocol, it

of Cultural Heritage (ICVBC) of the

the two QoR® substitutes and

would be possible to identify, based on

National Research Council (CNR) of

corresponding self-produced colour

the surface to be retouched, the best


because it is not composed of alizarin

solvent to be used for both application


and re-solubilization of the colours,

REFERENCES [1] UBALDI, Vanessa - Self-produced

analysis, Polymer Degradation and Stability.Vol.

Colours Based on Aquazol® 500. In DE

144, Elsevier, (October 2017), pp. 508-519.

LUCA, Daphne (Edited by) - Preservation



polymdegradstab.2017.09.007 [8 November





Collection of Fundamentals of Cultural Heritage Preservation and Conservation, 3rd

at: DOI:https://doi.org/10.1016/j.

2017]. [3] MODUGNO, Francesca; LA NASA, Jacopo; ORSINI, Sibilla; DUCE, Celia; SPEPI,

edition, Il Prato, 2018, in press. MARCO,

Alessio; TINÉ, Maria Rosaria; UBALDI, Vanessa;

Fiammetta; BERNAZZANI, Luca; DUCE,

DE LUCA, Daphne - Characterization and

Celia; SPEPI, Alessio; UBALDI, Vanessa;

ageing studies of Aquazol retouching paints


using techniques based on Pyrolysis, Poster

Stefano; TINÉ, Maria Rosaria; DE LUCA,

Session 2: Wednesday 11 May & Thursday

Daphne; MODUGNO, Francesca - Aquazol

12 May. In Conference Guide and Abstracts,



NASA, Jacopo; DI


and to investigate if, after their removal,

colours (Recipes A and B), QoR®

there are any traces of residues on

as binder for retouching paints. An evaluation

21st International Symposium on Analytical

colours have proven to be less stable

the surface, or within the preparatory

through analytical pyrolysis and thermal

and Applied Pyrolysis, Pyro 2016, Nancy,





Vanessa Ubaldi | Roberto Bestetti | Roberto Franchi | Emanuela Grifoni | Pier Paolo Lottici | Francesca Modugno | Richard Wolbers | Daphne De Luca

The use of aquazol® 500 as a binder for retouching colours: analytical investigations and experiments


- Critical Pigment Volume Relationship,

[14] PELOSI, Claudia; MARABELLI, Maurizio;


Industrial & Engineering Chemistry. Vol. 41,


Isseu 7, ACS Publication, (July 1949), pp. 1470-

ORTENZI, Floriana; PATRIZI, Francesca - Pro-


blematiche conservative degli acquerelli nel


Book). Available at: http://www.pyro2016.

RECH2: PROCEEDINGS, 2nd International


Meeting on Retouching of Cultural Heritage,

[8] WOLBERS, Richard C.; MCGYNN,

[8 November 2017].

Escola Artística e Profissional Árvore, Casa

Mary; DUERBECK, Deborah - Poly (2 Ethyl-2-

das Artes and Casa Allen, Porto, Portugal,

Oxazoline): a new conservation consolidant.

[12] Out of the three organic self-produced


24-25 October 2014. Available at: https://

In Painted Wood: History and Conservation,

colours and the equivalents QoR®, TGA was

BONINO, Valentina E.; UBALDI, Vanessa -


Proceedings of the Symposium, Williamsburg,

performed on only one organic colour, as

L’impiego dell’Aquazol per il ritocco pittorico

Proceedings [8 November 2017].

Virginia, 11-14 November 1994, pp. 514-527.

indicated in the text, because this technique in











in Italia: prove preliminari e avanzamento di

[6] CHIU, Thomas T.; THILL, Bruce P.;

[9] LEWIS, Mark; WOLBERS, Richard -

comparison to the others requires a greater

una sperimentazione, Sessione Poster. In

FAIRCHOK, William J. - Poly (2-ethyl-2-

Evaluation of the Suitability of Poly (2-ethyl-2-

amount of material, which is not available for

Giornata di Studio e Workshop sull’utilizzo

oxazoline): A new water and organic soluble

oxazoline) as a Potential Retouching Medium

all the samples, since they were used for other

dell’AQUAZOL - AQUAZOL: esperienze ed

adhesive. In GLASS, J. E. - Water Soluble

for Easel Paintings. Paper presented at the


applicazione nel panorama Italiano, La Venaria

Polymers, Advances in Chemistry. Vol. 213,

American Institute of Conservation at the

[13] The third organic pigment Irgazine®

Reale (Torino), Italia, 4 giugno 2014.

American Chemical Society, Washington D.C.,

Twenty Third Annual Meeting, June 4-11, St.

Ruby DPP-TR, used to prepare the same self-

1986, pp. 425-433.

Paul, Minnesota, 1995, p.76.

produced colour with the Recipes A and B





Annalisa; DE LUCA, Daphne; SELVA BONINO,


St. NW, Suite 320, Washington DC, 2011, pp.

France, 9-12 May 2016, p. 82, (Conference-

[7] VAN GELDER, Mark – Aquazol.

[10] WOLBERS, Richard - Giornata di Studio

and its corresponding organic colour QoR®,

Valentina E.; UBALDI, Vanessa - Aquazol



e Workshop sull’utilizzo dell’AQUAZOL, La

Pyrrole Red Deep, were not analysed with

based retouching colors: Preliminary Tests

Christopher; DUNN, Joanna - Painting

Venaria Reale (Torino), Italia, 4-5-6 giugno

this technique since the colour samples taken

and Advancement of an Experiment, Poster.

Conservation Catalog Volume III: Inpainting,


were insoluble in the solvents used in liquid

In BAILÃO, Ana; HENRIQUES, Frederico;

Paintings Speciality Group, AIC, 1156 15th

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[11] ASBECK, W. K.; VAN LOO, Maurice

restauro. Archeomatica, numero 0, Novembre 2009, pp. 24 -27.


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Golden Artists Colors,

Polyvinyl acetate resin;





AYAC characteristics of the retouching paints

Golden PVA colors;

will be summarized based on the treatment of a 17th-century oil on canvas painting attributed to Pietro da Cortona and his workshop. 1. INTRODUCTION 1.1. Historical Use of PVAC

PVAC resins have been used as a retouching medium in the field of




In 1991, Golden Artists Colors, Inc. introduced a line of specially

Kristin deGhetaldi (1) | Brian Baade (1) | Joyce Hill Stoner (1) | Jim Hayes (2) | Samantha Alderson (3)

formulated PVAC conservation paints

1. University of Delaware, 18 E. Main St. Old College room 302, Newark, DE, 19716; kdeghetal@yahoo.com; bbaade@udel.edu; jhstoner@udel.edu 2. Golden Artists Colors, Inc.188 Bell Road New Berlin, NY 13411; jhayes@goldenpaints.com 3. American Museum of Natural History, 79th St. and Central Park West, New York, NY 10024; salderson@amnh.org

nearly a decade later, the Union

based on a mixture of AYAA and AYAC manufactured by the Union Carbide

Corporation[2]. However,

Carbide discontinued the production of the PVAC AY resins and Golden ultimately halted production of their PVA Conservation Colors by 2010.

Abstract The field of art conservation has used Polyvinyl acetate PVAC for consolidation and retouching since

a new conservation paint line three

the 1930s. Its use as a retouching medium was first mentioned in a 1935 journal, Technical Studies in

years later. After much testing, the

the Field of the Fine Arts, published from 1932-42 by the Fogg Art Museum. PVAC paints were found


While conservators have continued

Conservation Paints

to use leftover reserves of the AY


resin line for retouching purposes, the


pre-made PVA Conservation Colors

potential medium for retouching by

offered some distinct benefits. In



2013, a renewed collaboration began

John Gettens




performed at the Fogg Art Museum,

and Golden Artists Colors, Inc. to

were presumably inspired in part by



an article published in a conservation

paints. Thanks to ongoing research

journal earlier that year which focused

spearheaded by objects conservator

on the use of polyvinyl acetate in

Samantha Alderson, efforts were

artists’ paints

already underway to identify and

resin was being used routinely as a



retouching medium, both as a water-

some of the discontinued AY resins.

miscible emulsion as well as a simple


solution binder that could be thinned

conservators, the











homopolymer tested




. These initial tests,

. By the 1950s, PVAC


University of Delaware contacted

with organic solvents


Alderson and subsequently reached

conservation scientist Robert L. Feller

to exhibit little or no discoloration upon aging, could be dissolved in a range of solvents including

provide conservators with pre-made

out to Golden Artists Colors to

and paintings conservator Mario

alcohols, glycol ethers, acetone, and toluene, and could maintain both clarity and reversibility.  Hoescht

PVAC conservation paints in 2017. This

explore the possibility of re-creating

Modestini began testing a range of

Mowilith 20 and Union Carbide AYAB were the typical PVAC resins used for inpainting. Collaboration

talk will briefly outline the history of

between Golden Artists Colors and painting conservators led to the introduction of Golden’s pre-made

PVAC retouching paints and discuss

a new line of PVAC retouching

PVAC resins at the National Gallery

PVAC conservation paints based on a blend of Union Carbide AYAA and AYAC in 1991. Mark Golden also

some of the specific properties of the

paints for the art conservation field.

of Art in Washington, ultimately

created custom-made retouching paints for the 1988-1992 treatment of Whistler’s Peacock Room in

new Golden line including molecular

This paper will outline some of the

identifying Union Carbide’s AYAB

the Freer Gallery of Art. Unfortunately, both the Mowilith and Union Carbide resins were discontinued

weight, gloss, solubility, and practical

preliminary analytical results from tests

resin as possessing the most desirable

causing Golden to cease production of the line in 2010. Continued interest in PVAC retouching

application tips with examples from

performed on the replacement PVAC

working properties

paints inspired Golden to collaborate with conservators and conservation scientists to reformulate


resin. In addition, practical working

transition temperature of AYAB was









. In 1959,


. As the glass

[5, 6, 7]

samples using a 220 nm filter. 5 µl

To assess changes in gloss, a BYK

of each samples was then injected

Micro-TRI-Gloss Meter was used

into a Waters Alliance® System

on all paint samples (readings were

2695 Separations Module equipped

obtained at 60 degrees). Resolubility

with a Waters 2414 Refractive

was assessed by applying cotton

Index Detector using a 300x7.8mm

swabs saturated in denatured alcohol

High Speed GPC Column (25

to the surface of the aged paints, and

minutes @ 35 deg C). Results were

the number of circles were recorded

interpreted using Millenium® 32

before the swabs effectively broke

Chromatography Manager Software.

AYAB) and the mixture was found to

resins from Union Carbide’s AY

original 50/50 mixture of two PVAC

at room temperature), Modestini

possess satisfactory working and aging

line have also become popular for

resins of different molecular weight,

would often interlayer resins with

properties. A set of colors bound in

other uses in conservation (e.g. as

Alderson suggested initially testing

higher glass transition temperatures

this mixture was provided to paintings

surface coatings, consolidants, etc.),

single resins as replacements. She

(e.g. Paraloid B-72) throughout the

conservators Wendy Samet and Dr.

a collaborative project was begun

provided Jim Hayes, the technical

inpainting process to effectively seal

Joyce Hill Stoner for their treatment

by Alderson and her colleagues to

director at Golden Artists Colors,



of James McNeil Whistler’s Peacock

identify potential substitutes for these

Inc., with five samples of resins that

and prevent the accumulation of

Room at the Smithsonian Institution’s

resins, the results of which will be

seemed to be promising substitutes


. In subsequent decades

Freer Gallery of Art in Washington

presented in a forthcoming publication

for the original mixture as well as

PVAC resin gained popularity as a

DC (the treatment occurred between


. They began by collecting samples

old samples of AYAA and AYAC for

retouching medium throughout the

1988-1992) and in 1991, Golden

of PVAC resin in a wide range of

comparative testing.


PVA Conservation Colors became


1980s, however, Union Carbide was

officially available for purchase


current manufacturers. These were

no longer producing AYAB, prompting

Nearly a decade later, Samantha

evaluated and compared to samples

scientists and conservators to identify

Alderson, objects conservator at the

of the discontinued Union Carbide

a replacement material. Conservation

American Museum of Natural History,

and Hoescht resins. The team used

scientist René de la Rie, then head of

learned that the Union Carbide AY

a variety of analytical instruments to

Golden’s technical staff produced

the Scientific Research Department at


evaluate and test the potential resins

five paint samples based on the

the National Gallery of Art, suggested

had been discontinued and that

including Fourier Transform Infrared

potential resin replacements identified

that conservators consider using a

Hoechst’s Mowilith 20 was no longer

Spectroscopy (FTIR) to characterize

by Alderson and her colleagues in

PVAC resin manufactured by the




addition to re-creating the original 1:1

German company Hoechst. Mowilith

she learned that that some PVAC

Permeation Chromotagraphy (GPC)

AYAA/AYAC mixture for comparison.

2.2 Gel Permeation

know which resin they were using).

20 possessed a viscosity and refractive

substitutes available through certain

to measure the molecular weight.

Each of the five resins as well as the

Chromatography (GPC)


index close to that of AYAB (RI=1.467)






[6, 7]

. While


community. By










2. MATERIALS AND METHODS 2.1 Mechanical, Solubility, and

observe any potential cracking, flaking,

samples and sent them to painting

Color/Gloss Testing

or delamination. Finally, a Xrite CI7800

conservators deGhetaldi, Baade, and

Benchtop Color Spectrophotometer

Stoner to perform a series of blind

was used to monitor any potential

tests to determine which had the

shifts in color (calculated using the

most appropriate working properties

CIELab delta E masstones).

(the paints were labelled with a code

. Consequently, Golden

by Kristin deGhetaldi, a paintings

as the control) were mixed with





continued to mix dry pigments

discontinued their PVA Conservation


with Mowilith 20 or with leftover

colors by 2010 as a replacement resin



(PW6), quinacridone red (mixture of

reserves of the discontinued AYAB

had not yet been identified.

formulation of the Golden PVA

PR 206 and PR 202), and raw umber


Colors. DeGhetaldi

(PBr7). Paint drawdowns (10 mL)






expressed interest in obtaining pre-

1.2 Recent Developments in PVAC

had been contracted to conserve

were created and then subjected to a

made retouching colors bound in

Paints Used in Conservation

a large 12-by-20 foot oil-on-canvas

series of tests before and after short-

painting attributed to Pietro da

term light aging. Artificial aging was

PVAC resin. Golden began testing

The PVAC resins that have been

a 50/50 mixture of AYAC (lower



Cortona in collaboration with fellow

performed under ambient conditions

molecular weight than AYAB) and

purposes have not been produced

paintings conservator Brian Baade.

using a filtered Xenon arc-source

AYAA (higher molecular weight than

for nearly a decade. As other PVAC

Rather than trying to replicate the

with a radiant exposure of 510 kJ/m2

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manually manipulating the substrate Golden prepared all five of the

1:1 AYAA/AYAC mixture (designated

[9, 10]


(acrylic-primed canvas) in order to

In 2013, Alderson was contacted


through the surface of the paint samples. Flexibility was assessed by




resin, other paintings conservators


at 340 nm for a period of 405 hours.

fairly low (remaining somewhat tacky

so that the conservators would not conservators


Gel Permeation Chromatography

concluded that they could not tell the

(GPC) was performed on four

difference between the workability

pigmented samples bound in the

and re-solubility of the five samples

final selected resin: Prussian Blue (PB

from that of the original Golden PVA

15:1/PV 23/PBk 9), Titanium White

Conservation Colors (1:1 AYAA/

(PW6), Yellow Ochre (PY43), and

AYAC). With the analytical and

Burnt Umber (PBr7). All four samples

empirical testing completed, Alderson

were prepared by adding 1.5 mL of

suggested that Golden select Vinavil

tetrahydrofuran to approximately 10-

Raviflex BL5S as their PVAC binder

20 mg of paint. After centrifuging the

as her research found that this resin

samples for 30 seconds, the dissolved

possessed physical properties that

resin was obtained from each of the

were most like Mowilith 20 [11].

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3.1 Mechanical, Solubility, and Color/

the human eye). Very minimal changes

Gloss Test Results

in re-solubliity were also observed, an

Golden’s initial tests on Vinavil Raviflex

expected outcome as PVAC resins have

BL5S have yielded promising results when

shown little to no signs of cross-linking

compared to the control (1:1 AYAA/

over time.

AYAC). It showed minimal differences from the control when subjected to

3.2 GPC Molecular Weight Results

the same series of tests (see Tables 1A

Five samples were subjected to

and 1B) both before and after short-

GPC analysis in order to confirm the

term aging. The Vinvavil Raviflex BL5S

molecular weight distribution that has

even slightly outperformed the control

been reported in the literature and by

on some tests. For example, the delta

the relevant manufacturer (see Figure

E values measured for each of the new

1). Samples of AYAF, AYAA, and AYAC

PVAC colors before and after light aging

were chosen as they span a wide

were all below one (not discernible to

molecular weight range and the latter



two resins were used as the primary

amu. When comparing this value to

binders for Golden’s previous PVA line.

the reported molecular weight range

Two paint samples were also run: burnt

(22,000-30,000 amu), this falls in line

umber (PBr7) bound in 1:1 AYAA/

with the trend observed for all three

AYAC and cadmium red light (PR

AY resins, as AYAF, AYAA, and AYAC

108) bound in Vinavil Raviflex BL5S. As

all possess weight average molecular

some of the samples did not generate

values that are greater than their

narrow distributed single peaks, only an

number average molecular values

be achieved by increasing the amount

approximation of Vinvavil’s molecular

[8, 12]. Additional testing using GPC

of ethylene glycol/ propylene glycol

weight could be calculated. Based on the

and Size Exclusion Chromatography

monomethyl ether. Additions of the

logarithmic relationship between the

(SEC) will likely reveal more precise

pure resin (Vinavil Raviflex BL5S) pre-

elution time and molecular weight, the

approximations for both the weight

dissolved in an alcohol, a mixture of

weight average molecular (as opposed

average molecular and number average

alcohol and ethylene glycol/propylene

to the number average molecular) was

molecular values.

glycol monomethyl ether, or pure

calculated to be approximately 33,000



Like the earlier PVAC AY resins, the new line of Golden PVA Conservation

Vinavil Raviflex BL5S



Slightly less


colors (made with the replacement

Quina-cridone Crimson

Control (1:1 AYAA/AYAC)





resin Vinavil Raviflex BL5S) can be

Vinavil Raviflex BL5S



Slightly more flexible


dissolved for retouching purposes using


Control (1:1 AYAA/AYAC)





alcohols.To slow down the evaporation


Vinavil Raviflex BL5S



Slightly more flexible


rate (allowing for more blending and richer glazes), a small amount of ethylene glycol or propylene glycol



Control (1:1 AYAA/AYAC)




Vinavil Raviflex BL5S





Control (1:1 AYAA/AYAC)




-done Crimson

Vinavil Raviflex BL5S





Control (1:1 AYAA/AYAC)





Vinavil Raviflex BL5S




Titanium White

Table 1B


Chart summarizing test results relating to resolubility and color change of PVA paints before and after short-term aging.

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the paint. All of these factors can be




Retouching Paints




monomethyl ether can be added to



C  omparison of chromatograms collected using GPC associated with AYAF, AYAA, AYAC and original and new PVA paint samples.

3.3 Working Properties of PVAC


Table 1A • Chart summarizing test results relating to gloss and flexibility of PVA paints before and after short-term aging.


Control (1:1 AYAA/AYAC)

Titanium White

Figure 1

monomethyl ether (e.g. Arcosolv PM) can be added to the alcohol diluent. To achieve a more matte appearance, the PVA colors can be further thinned with alcohols (e.g. ethanol) or mixed with additions of dry pigment and/ or matting agents (e.g. glass microballoons). Conversely, a thicker and/ or more glossy paint consistency can

controlled to achieve the desired level of gloss and open working time. One advantage of using the pre-made PVAC conservation paints is that the colors are well and evenly dispersed. One challenge that faces conservators who hand-mixing dry pigments into a fast-setting resinous medium is to create a paint that will not “sink” over time, a phenomenon due in part to poor pigment dispersion. One potential drawback to all PVA retouching paints is the low refractive index of the resin (1.4665). This is easily remedied by the superimposition of a glaze containing a higher refractive index (e.g. Laropal A81) or the application of a surface varnish with similar properties. PVAC

resins are polar by nature and therefore do not wet well onto pigments that are non-polar such as carbon black [13]. One solution to counteract this problem is to add minute amounts of alcohol soluble dyes (e.g. Orasol® Dyes) that have satisfactory lightfast ratings; however, the dyes should be used sparingly and preventive measures (e.g. coating with a varnish containing UV




appropriate lighting conditions) should be considered if dyes are added to the paints. This particular method (using the newly formulated PVA paints) was used to reintegrate large sections of paint loss on The Triumph of David in order to achieve a satisfactory degree of saturation in darker passages (Figure 2). Like some of the AY resins, the glass transition temperature of the resin in the new PVAC paints is close to room temperature (the manufacturer recommends storing the pure resin at a temperature above 20 degrees C). Consequently, it is advisable to coat the retouching paints with an appropriate varnish layer possessing a higher glass

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PVA samples at the Microscopy and Mechanical Testing (MMT) Center at the University of Delaware.

REFERENCES [1] GETTENS, Rutherford J. - Polymerized vinyl acetate and related compounds in the restoration

Figure 2 • Before (left) and after (right) retouching large area of loss in The Triumph of David attributed to Pietro da Cortona using the newly formulated Golden PVA Paints combined with Orasol Dyes (photo courtesy of Villanova University).

transition temperature in order to avoid the potential accumulation of dust/grime (although this is likely only to affect areas that are covered with thick applications of the paints)

appropriate option for making paints for use in inpainting. PVAC resins have been shown to exhibit little or no discoloration upon aging, are soluble in



a wide range of solvents, and maintain

For removal of the paints, ethanol can

both clarity and reversibility.  The loss of

be used; however, if the artwork is

earlier sources of such a resin prompted

sensitive to alcohols, toluene has been

the discontinuation of Golden PVA

successfully used to remove PVAC

Conservation Colors. Research began

resins after short and long-term aging.

to find a new replacement resin, which would possess similar or superior


properties and allow Golden to resume the production of pre-made


Previous research and studies have

PVAC conservations paints. Extensive

shown that PVAC resins are an

testing by scientists and conservators

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resulted in the selection of Vinvavil Raviflex BL5S as a replacement resin. Golden Artists Colors has relaunched their PVA Conservation Colors and they are now available to conservators. ACKNOWLEDGMENTS The





acknowledge Rachel Modrovsky for her assistance with the preliminary tests performed on the Vinavil Raviflex BL5S paints. We are also indebted to Dr. Shuang Liu for performing Gel Permeation Chromatography on the

Proprietary Painting Media. AIC Preprints, Fourth Annual Meeting, Dearborn, Michigan,

no. 2 (2009), pp. 16–17. [10] ALDERSON, S. - Response to Supplier for

of objects of art. Technical Studies in the Field of

1976, p. 126.

AYAA Sought, Conservation DistList. Available

Fine Arts.Vol. 4, no. 1 (1935), pp. 15–27.

[6] BERGER, Gustav Adolf. - Inpainting using

at: http://www.cool.conservation-us.org/

[2] STONER, Joyce Hill. - America’s colormen:

PVA medium. In Cleaning, Retouching and


Bocour, Levison, Gamblin, and Golden. In

Coatings: Technology and Practice for Easel

(12 July, 2017).

Modern Art, New Museums: Contributions

Paintings and Polychrome Sculpture, Preprints


to the Bilbao Congress, 13–17 September

of the Contributions to the Brussels Congress,

C.S., WILLIAMS, R.S., and YOUNG, G.R. -

2004. London: International Institute for

3–7 September 1990. London: International

Substitutes for discontinued poly(vinyl acetate)

Conservation, 2004. pp. 189–192.

Institute for Conservation, 1990, pp. 150-155.

resins used in conservation (forthcoming publication in the Journal of the American

[3] CLARKE, William J.; IVES, Herbet Eugene

[7] BERGER, Gustav Adolf. - Inpainting using

- The use of polymerized vinyl acetate as an

PVA medium – Inpainting using PVA Medium:

artist’s medium.Technical Studies in the Field of

Mario Modestini’s Pioneering Research – In

Fine Arts. Vol. 4, no. 2 (1935), p.4.

BERGER, Gustav Adolf; RUSSELL, William H.

BL 5S. Available at:

[4] DIGNEY-PEER, Shawn, et al. The imitative

ed. - Conservation of Paintings: Research and


retouching of easel paintings. In STONER,

Innovations. London: Archetype Publications.,

5s%20-%20a%20(engl).pdf (12 July, 2017).

Joyce H.; RUSHFIELD, Rebecca A., eds. – The

Ltd., 2000. pp. 191–216.

Institute for Conservation). [12] VINAVIL - Technical data sheet. Raviflex http://www.vinavil.com/


Conservation of Easel Paintings. London:

[8] UNION CARBIDE. - Polyvinyl acetate

R.,TOWNSEND, J., and GRITT, S. - The imitative

Routledge, Taylor & Francis Group, 2012. pp.

resins for coatings and adhesives. Danbury,

retouching of easel paintings. In STONER,


CT: Union Carbide Chemicals and Plastics

Joyce H.; RUSHFIELD, Rebecca A., eds. – The

Company Inc., 1989.

Conservation of Easel Paintings. London:

[5] FELLER, R. - Exposure Tests on Traditional Systems

[9] ALDERSON, S. - Union Carbide no longer

and Characterization of Certain Modern

manufacturing PVAC resins. AIC News Vol. 34,




Routledge, Taylor & Francis Group, 2012. pp. 607-634.

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Keywords Watercolour markers; Fillers; Varnish; Chromatic reintegration techniques.


The purpose of this work was to assess the usage of watercolour markers in the context of the conservation and restoration of art paintings and systematically assess its behaviour under different fillers and



Liliana Cardeira | Ana Bailão Sérgio Nascimento (3) (1, 4)

(1, 2, 3)

| João Linhares


The use of colour markers is well


known in the field of the artistic materials, but their use in the context of the chromatic reintegration on

The study is being conducted within

2. MATERIALS AND METHODS To assess the use of watercolour


the framework of the conservation

markers of W&N

still unknown. The purpose of this

and restoration of a set of paintings by

the chromatic reintegration of art

project was to present preliminary

Adriano de Sousa Lopes (1879-1944)

paintings, watercolour markers were

results of the assessment of the use


.This artwork belongs to the painting

tested on three different types of

of watercolour markers in chromatic

collection of the Faculty of Fine Arts,

fillers using different reintegration



University of Lisbon (FBAUL), Portugal.

techniques.This assessment was done

markers were tested under several

Researching the sustainability of use of

two-fold. Under visual inspection of

conditions of technique of use onto

retouching materials remains a priority

the chromatic properties, enlarged

several surfaces to ascertain whether

in the 21th century in the context

by the usage of a digital microscope,

they can be used on the retouching

of restoration. The watercolour is a

and by the means of a hyperspectral

practice [1, 2].

widely used and studied material in


chromatic reintegration

properties of the object under


1. F aculty of Fine Arts, University of Lisbon; Largo da Academia Nacional de Belas Artes nº 14, 1200-005, Lisboa; E-mail address: lilianacardeira@gmail.com; 2. R  esearch Center for Science and technology of the Arts - Portuguese Catholic University, Centre Regional of Porto, CITAR, Portugal; Rua Diogo de Botelho 1327, 4169-005, Porto; E-mail address: ana.bailao@gmail.com; 3. Centre of Physics, University of Minho, Gualtar Campus, Gualtar, 4710-057, Braga, Portugal; E-mail address: jlinhares@fisica.uminho.pt; 4. H  ERCULES Lab and Chemistry Department, Evora University, Portugal ;Palácio do Vimioso Largo Marquês de Marialva, nº8, 7000-809, Évora; smcn@fisica@uminho.pt

Figure 1 • Watercolours in pens –form from the Winsor & Newton Company. Liliana Cardeira©.





. There are


several watercolour brands available,


(Figure 1) in

system. The


analysis were compared. Recently,




The aim of this work is to present preliminary results of the use of watercolour

produces a non-neglected visual

used by professional conservators that

markers in chromatic reintegration. The behaviour of 15 watercolours of Winsor &



can be found in common retailer, and

form of a pen became available.

Newton® markers were tested to ascertain whether these are useful for use in the

colours, when markers are used

To conduct the experiments the


it is possible to find watercolours in

retouching practice. Three different types of reintegration techniques were used to test the two brush tips: mimetic, pointillist and tratteggio, and three testing surfaces

These findings seem to indicate

a wide variety of forms: pans, tubes,

Winsor and Newton® watercolour

were created by applying four fillers over a wooden board covered by calcium

that the watercolour markers

crayons, coloured pencils, even stones.

markers (Table 1) were used. They

carbonate and rabbit glue, Modostuc® and Gesso Primer. To examine the process of

can be used during the process

Nevertheless the wide availability of

are much cheaper than their alcohol

the reintegration of the markers on the surfaces an USB digital microscope was used

of reintegration, but the fillers

watercolours, their usage as an option

based version but non-refillable.

to visually assess its details and a hyperspectral imaging system was used to assess

and varnish in use has to be

of chromatic integration in restoration


its chromatic properties. It was found that the used fillers and accompanying varnish

taken into account.

is yet to be assessed systematically.

markers enable the spread of its



the art




Mock-ups with different fillers were

the watercolours four varnishes were

water. According to the manufacturer

created to compare the behaviour

applied: Paraloid B72®, Laropal 81®,

Tratteggio and Selezione cromatica

the colour blending varies depending

of 15 colours from the watercolour

Retouching varnish of Talens® and


on the paper or substrate used so

markers of Winsor & Newton® (as

retouching varnish of W&N®. Each

reintegration techniques over different

it is paramount to test the markers

described in Table1). The fillers were

one of the 15 watercolour markers

fillers. No varnish was used in this case.

over different fillers to assess their

applied over a wooden board with

were tested on each one of the three

Care was taken to reproduce the

behaviour. It was decided to test the

dimensions of 30cm x 23cm, and were

fillers, each one under one of the four

same pattern and painting technique

markers with three fillers and four

made from: calcium carbonate and

varnish used, on a combination of 12

over the different fillers.

varnishes to check is functionality and

rabbit glue from CTS; Modostuc®

conditions per colour.

to test their influence on the final

from Plasveroi International; and

Each colour combination was then

react and interact on the distinct

colour saturation.

Gesso Primer from Talens®. Over

assessed under a visual inspection and

reintegration technique is key to

the hyperspectral system.To extend the

validate the process of the selection

analysis of the chromatic reintegration,

of the proper chromatic reintegration

three different reintegration techniques

technique in each case. To asses this

were used and evaluated.

reaction and interaction of the colours

Table 1 • Pigments, references of watercolour markers and American Society for Testing Material (ASTM) [6] . Liliana Cardeira®. COLOUR NUMBER


brush tips, namely, mimetic, pointillist,

colours without the need of a brush or



Understanding now the colours

Figure 2 • Tests of markers in three types of fillers with different reintegration techniques. Liliana Cardeira and Ana Bailão®.

over the fillers a visual inspection was

119 – Cadmium yellow pale hue



2.1. Visual inspection of the

266 – Gamboge hue



chromatic reintegration techniques

552 – Raw Sienna

PY42, PY83, PR179


with the watercolour markers.

554 – Raw Umber

PY83, PV23


074 – Burnt Sienna



076 – Burnt umber

PY83, PR122, PBk7, PBr7


061 – Burnt red

PR188, PY83, PV23


95 – Cadmium red hue



545 – Quinacridrone Magenta



522 – Phthalo green



312 – Hooker’s green Dark

PB15:3, PY83


514 – Phthalo blue (red shade)



515 - Phthalo blue (Green shade)



337 – Lamp black



331 – Ivory black

PBk7, PY83, PBk9


Liliana Cardeira | Ana Bailão | João Linhares | Sergio Nascimento

. Figure 2 represents the different

The markers in pen-form have the

made. The behaviour of the watercolour markers over three fillers using different



advantage of having a fine point at

was made by using an USB digital

one end and a flexible brush tip on

microscope Dino-Lite Pro brand -

the other for fine or thick strokes,

AM4013-FVW model with 1.3 Mpixel

respectively. The fine tip has a more

resolution.This microscope is portable,

accurate trace but thicker and the

equipped with one switchable LED

brush tip allows the application

UV light and enabled an augmentation

of colour layers.

of the image viewed by 200x times.

Some of these

Figure 3 • Markers under different fillers and distinct varnishes. Anabela Cardeira, Carina Carvalho and Liliana Cardeira®.

the substrate material were observed

and as such the results should be

materials have a lightfast and are highly

This technique was used to verify in

and analysed in order to estimate the

accepted, even if small differences are

pigmented such as Burnt Sienna, Burnt

detail the behaviour of the material

best reintegration technique over the

to be assumed.

red, Cadmium red hue, Phthalo green,

in the distinct types of fillers, as the

better ground layer.

Phthalo blue (red shade), Phthalo blue

magnification using the USB microscope

(Green shade) and Lamp black. In the

enable a better visual comparison.

About the methodology, it was only

2.2. Inspection hyperspectral of the

used the digital microscope Dino-Lite

chromatic reintegration technique with the watercolour markers.

context of this research, different types

The easy of the colour spread, the

for observation of the samples, but in

of reintegration techniques were used

simple of colour application, and the

this case all samples were assessed

to test the fine tip and the flexible

adsorption of the watercolour paint by

by the same experienced observer





properties of the watercolour markers

Using watercolour markers in chomatic reintegration


under different varnishes (Paraloid

about the system can be found

markers, different fillers and varnishes,

such wide areas. Figure 4 represents

B72®, Laropal 81®, using retouching


. The hyperspectral data

and then compared. By taking mock-

the process of image acquisition using

varnish of Talens® and retouching

was calibrated using the spectrum of

up 1 as represented in Figure 3 as an

the hyperspectral imaging system.



the light reflected from a flat uniform

example, using the first yellow marker

(calcium carbonate, Modostuc® and

reference present in the scene during

under Paraloid B72 as reference, the

Gesso Primary) (as represented in

the process of image acquisition. The

colour difference was estimated

Figure 3 and Table 1) the mock-ups

spectral reflectance of each pixel of

against the other three varnishes

As shown in Table 2, the watercolour

were digitized with a hyperspectral

the image was corrected for dark

and averaged. In all cases, the colours

markers can be used in all the

imaging system to obtain their

noise, spatial non-uniformities and

under Paraloid B72 were used as

tested reintegration techniques, but

spectral information combined with

stray light. The spectral radiance of

reference.The averaged area included

sometimes the fillers do not produce

their spatial information.

each image pixel was then estimated

45 pixels horizontally and 10 pixels

the desired outcome.

The hyperspectral imaging system

from the reflectance data assuming

vertically, with an approximated area

According with the observations

was comprised by a fast-tuneable

the CIE D65 standard illuminant

of 7813 mm . The standard deviation

with the digital microscope Dino-Lite,

liquid-crystal filter coupled with a


and converted into the CIELAB

was also estimated as a measure of

about the colour spread, the colour

monochromatic digital camera and a

colour space coordinates assuming

the computed uncertainty.To estimate

application, the adsorption of the

zoom lens.The acquisition was carried

the CIE 1931 standard colorimetric

the variations in colour induced by

watercolour paint by the substrate

reintegration technique was the

the three reintegration techniques

from 400 nm to 720 nm in 10 nm steps,


the three fillers and varnishes for

material and the capability of gradually

pointillism. The filler with best results

over the three fillers.


the same watercolour marker, the

building up the colour using multiple

was the calcium carbonate.

x 1024(V) pixels with a field of view

averaged across a fixed area over

colour difference between one of

layers, with the last layer not affecting

Table 2 presents a summary of the

Dino-Lite microscope, were only

of about 7º x 5º. More information

all the combinations of watercolour

the possible combinations onto the

the bottom layer, the most suitable

authors findings when experimenting

uniform and round over calcium

of W&N®)



with a spatial resolution of 1344 (H)




The CIELAB coordinates




Figure 5 • Images of mimetic, pontilhism, tratteggio technique obtained with a USB digital microscope Dino-Lite Pro brand - AM4013-FVW model with 1.3 Mpixel resolution. Ana Bailão®.

The dots, when observed with the

others was estimated by computing the Euclidean Distance between the


two pairs of colours in the CIELAB colour space by:

Gesso Primer

In the application of colour, this spreads Easy application in 1st and 2nd layer In the application of the 3rd and 4th layer begins to create textures

Calcium carbonate

In the application of colour, this spreads Easy application in 1st and 2nd layer In the application of the 3rd layer begins to create textures

CIELAB colour space provides a numerical representation of the visual chromatic perception. As such, by estimating a numerical distance in such three-dimensional space by using the former equation, a visual chromatic Figure 4 • Spectral imaging setup for the mock-up acquisition (Left) and the hyperspectral imaging system (right), João Linhares and Sérgio Nascimento®.

difference is directly related


[9, 12]

Only using hyperspectral images is it possible to have access to both the spatial and spectral information over


Liliana Cardeira | Ana Bailão | João Linhares | Sergio Nascimento


Colour application, very difficult



Easy application Uniform points in the 1st and 2nd layer

Easy control Less saturation and less porous Traces become thinner

Easy application It allows you to create burnish Uniform points in the 1st and 2nd layer

It allows you to create fine traits

Easy application It is stained due to the porosity of the mass In the 2nd tier points are spreading

Thick strokes and difficult to be controlled Features spread Greater absorption, influencing trace and colour saturation

Table 2 • Results found between different types of fillers with different types of chromatic reintegration techniques. Liliana Cardeira and Ana Bailão®.

Using watercolour markers in chomatic reintegration


assess the colour changes across

change with the varnish Talens® while

of the markers according to the

different varnishes. It was found that,

in sample 3, it is the varnish Laropal

pigment, filler and varnish has to be

the uniformity of the marker was

81® that it is more accentuated.

done first, as the colour differences

visually recognizable and quantified by the estimated colour differences

demonstrate, since the colour changes 4. CONCLUSIONS

with values higher than the expected threshold for complex images (DE of

colour, on the same filler but under It was found that the used fillers and

diverse varnish was greater than the

). This was found by comparing

accompanying varnish produces a

threshold of the colour difference

all the possible combinations of fillers

non-neglected visual difference in the

detection for complex scenes. This

and varnishes and estimating the

obtained colours, when markers are

material doesn´t need watering in

colour differences higher than the 2.2

used to reintegrate art paintings.

pigment, and ends up generating a



Figure 6 • Results with microscope Dino-Lite in various fillers with the pointillist technique, for magnifications of 200X. Liliana Cardeira®.

threshold limit of discrimination. It was

It was found that the fine point

assumed that if the colour difference

enabled conservators to achieve

The hyperspectral system has the

carbonate. With Modostuc® the dots

5.8 (±2.7) and 7.1 (±3.3) to mock-up

was higher than the threshold, the

more control when performing the

advantage of good spatial resolution,

adopt an irregular round shape. It was

1, 2 and 3, respectively, and considering

samples were visibly different. With

distinctive retouching, especially using

as good as the human eye at the same

also difficult to apply a flat and regular

only the chromatic changes, discarding

this technique it was possible to

the pointillism technique. It was also

distance of viewing, nevertheless the

layer of colour over Modostuc® and

the luminance information, the results

register a very significant change in

found that the fillers influenced the

colour space used to perform the

Gesso Primer. (Figure 5).

obtained were 3.9 (±2.4), 5.3 (±3.0)

sienna burnt, hooker’s green dark, blue

brushstroke of the markers and the

estimations of the colour differences

The deformation of the points

and 5.7 (±3.7), for mock-up 1, 2 and

Phthalo (green shade) and raw sienna

saturation of the colours. The flexible

is known not to be perfectly uniform

and the influence of the fillers were

3, respectively. This was estimated by

in mock-ups 2 (Gesso Primer) and 3

brush likewise allowed for uniform

(see reference [13]), nevertheless since

examined at magnifications of 200X.

averaging the chromatic coordinates of

(Modostuc®). However, mock-up 1

underpainting, more saturated in

this is a comparative study, the results

As can be seen in Figure 6, the

an area of equal size across each filler

(Calcium carbonate) presents very

porous fillers, like Modostuc®. These

can be used and compared among

pointillist technique had a different

and varnish combination, and by using

stable pigments: cadmium red hue,

markers were highly pigmented and

each other.

behaviour depending on the fillers of

the colour ∆Eab formula as described

sienna burnt, burnt red and Phthalo

since they were water-based they

the ground layer. These results seems

in the Materials and Methods Section.

Blue (red shade).The change of varnish

provided a permanent ink flow. This

to support that the best reintegration

Having the same filler and the

depends on the fillers. In mock-ups 1

characteristic was good for pointillism

technique is the pointillism over the

same marker it was possible to

and 2, it is possible to see the colour

but did not allow blending or the creation of hues gradation when

calcium carbonate filler.

more than one layer was needed.

Using the hyperspectral imaging it was found that there was a great visual




possible to use watercolour markers

perceived colour of the watercolour




during the process of reintegration,

marker (Table 3). The average colour




especially when working with small

Liliana Cardeira | Ana Bailão | João Linhares | Sergio Nascimento

Scientific article: F.; A ., Candeias, A.; Nascimento, S.; Linhares,


Table 3 • Results of the average colour difference and luminace. João Linhares®.

REFERENCES [1] Cardeira, L.; Bailão, A.; Baptista Pereira,


Euclidian distance was of 4.8 (±2.6),

faster and cost-effective process.

The tests proved that it was

impact of the filler and varnish over the

difference estimated using the CIELAB


between the same water marker

chromatic losses to be reintegrated with saturated colours. The selection

J. – Using watercolours markers in chromatic reintegration: a case study. 5th International Conference, YOuth in Conservation of Cultural Heritage, YOCOU 2016. [2 (4)] BAILÃO, A. - Critérios de intervenção

e estratégias para a avaliação da qualidade da reintegração cromática em pintura. Porto, Universidade Católica Portuguesa (2015): pp.250-256. [3] CARDEIRA, Liliana - Conservação e Restauro das obras do pintor Adriano de Sousa Lopes da Colecção de Pintura da FBAUL. FBAUL,

Using watercolour markers in chomatic reintegration


Dissertação de Mestrado, (2014).

– Porto, Matrizes da Investigação em Conser-

[4] BAILÃO, A. - As técnicas de Reintegra-

vação e Restauro I (2014): pp. 13-41.

ção Cromática na pintura: revisão historiográ-

[11] LUO, M. R., CUI, G., RIGG, B.” The

fica. Espanha, Ge-conservacion, nº 2 (2011): pp.

development of the CIE 2000 colour-


difference formula: CIEDE2000”. Color Res.

[7] SÁNCHEZ ORTIZ, A. et all. “Investigación sobre la estabilidad química y óptica de

[13] Aldaba, M. A. et al. “Visual sensitivity to colour errors in images of natural scenes”. Vis Neurosci 23, 2006, pp. 555–559.

Appl. (2001) 26: pp. 340–350. doi:10.1002/ col.1049.

Website: [5]

materiais contemporáneos para reintegración





cromática”. In IV congreso del GEIIC, Cáceres,

Book Chapter:

colour markers. Available at: http://www.

2009. Cáceres: GEIIC (2010): pp. 195-205.

[6] AA.VV. - Herramientas integradas de






water-colour-markers [10-07-2016].


análisis espectrales y colourimétricos aplicadas

NASCIMENTO, S.M.C. “Correlated Colour

a la restauración de pintura. In Conservación

temperature preferred by observers for

de Arte Contemporáneo, 14ª Jornada. Spain:


illumination of artistic paintings “, J. Opt. Soc.

Museo Nacional Centro de Arte Reina Sofia,

lightfastness of colourants used in artists

Am. A. (2008), 25(3): p. 623-630.

2013, pp. 33-42.

Materials (D4303) Specification for artists





[9] CIE, Colourimetry, in CIE. 2005. pp. 1-82.

Watercolour paints (D5067). In http://www.

alteração de cor de alguns guaches e agua-

[12] Linhares, J. M. M., Pinto, P. D., & Nasci-

astm.org/Standards/D4303.htm (2016/ 07/

relas utilizadas na reintegração cromática de

mento, S. M. C. (2008). The number of discer-

bens culturais”, Universidade Católica Editora

nible colors in natural scenes. Journal of the

[10] BAILÃO, A. “Avaliação colorimétrica da


Optical Society of America A, 25(12), 2918.

Liliana Cardeira | Ana Bailão | João Linhares | Sergio Nascimento


Nome artigo


Keywords Filling; Colour re-integration; Sculpture;


Unfired clay; Plasticine; Plaster cast.





opened an exhibition of works by

Martina Vuga

the sculptor Alojz Gangl (1859 – 1935) in 2010. He was the beginner

National Gallery of Slovenia; Puharjeva 9, Ljubljana, Slovenia; martina_vuga@ng-slo.si

of the revival of sculpture in the Slovene lands and the doyen to the first generation of Slovene earlymodern sculptors. (Fig. 1) In the history of Slovene sculpture, he is known above all as the author of the first Slovene public monument, which was erected, to poet and


Figure 1 • Alojz Gangl | (© Bela Krajina Museum)

national awakener Valentin Vodnik. [2]


Prior to being presented in the exhibition, a number of selected

After initial examination the condition

sculptures from different collections

of the sculptures was discussed,

and owners needed to be restored.

and goals for the treatment were

When they were brought to the

established. Conservation treatment

conservation-restoration workshop

should return them to visual and

in the National Gallery of Slovenia,

physical state as close to “original” as

certain artworks were in a very poor

possible and suitable for exhibiting.

state of preservation because of the

That meant that dirt needed to be

fragility of the material itself and

cleaned from the surfaces; losses

frequent or inappropriate handling

would be compensated; and finally

and/or storing in the past. The poor

areas of restoration would be visually

state of conservation made handling

integrated with the original surfaces.

and exhibiting impossible.

Because of the materials not so

Prior to the exhibition Alojz Gangl. A Sculptor on his Way to Modernism (2010) National

with similar materials. Restoration-

Gallery of Slovenia had to restore a large number of his sculptures. This paper presents


three case studies and focuses on the treatment of losses to decorated surfaces.

and materials varied according to

Each described sculpture is made of a different material: unfired clay, plasticine


and plaster. The purpose of this article is to present the conservation treatments

materials of the sculptures. It was

Sculptures from Gangl’s oeuvre vary

common in the restoration practice,

of different materials, which share the same approach to aesthetic presentation.

not possible in the three discussed

When we considered damages aesthetically unacceptable, the chosen approach


in material, from traditional sculpture

we had to choose the materials and

to fillings and colour reintegration for all three sculptures was the same: to fill

for the reversibility of the materials

materials as plaster, wood, terra cotta,

methods on a case-by-case basis.

and retouch. In two cases, the procedures of filling and colour reintegration were

and treatments. The principle of re-

done literally in a single step.

treatability (keeping open the options

We would like to share the conservation treatments of some materials such as

for future treatments) seemed more

unfired clay and plasticine which are rarely documented and we would also like to

realistic in this situation.

present a few decisions that are in a certain way different from the past practice












bronze and stone to more unusual,

The paper describes three selected

provisional and unstable materials

case studies. The first discussed

like unfired clay, plasticine and other

sculpture is made of unfired clay, the

mixed materials.

next one is a plaster cast and the third

one is made of plasticine. All three

was of prime consideration, and so

cases share a certain decision: filling

was the potential retreatability.

and colour re-integration (almost) in a


single step.




described previously, we decided on a different material, i.e. a coloured wax-

2.1 Conservation-restoration

resin mixture. It is a system without

treatment of St. Agnes, unfired clay

water, and the added material can be

The first case study describes the treatment of the sculpture of St. Agnes (38.5 x 14 x 11.5 cm), c 1924, from the

Figure 2 • Alojz Gangl, St. Agnes, unfired clay, before treatment; (© National Gallery of Slovenia, photo: M.Vuga).

Figure 3 • Alojz Gangl, St.Agnes, unfired clay, after treatment (© National Gallery of Slovenia, photo: M.Vuga).

means of appropriate solvent. The




beeswax and dammar resin. To bulk

Bela Krajina Museum (inv. no. U66). It is From described cases, we can

out the fill, chalk (Ca carbonate)

conclude there is no generally

is used. By adding pigments to the

of the 1990s on a clay Sarasvati statue



mixture, we matched the colour

2.1.1 Condition before treatment

from the Todai-ji Buddhist temple in





Nara, Japan. Traditional Japanese glue

sculptures made of unfired clay.

original surface of the paint layer. The

before the treatment revealed that

made of seaweed or its mixture

2.1.3 Materials and methods

use of this mixture renders possible

clay core had suffered from multiple

with synthetic resin was used for


remodelling and colour reintegration

mechanical injuries. Parts of it have

consolidation of clay and paint layers.

of St. Agnes encompassed local

been broken and lost, e.g. the tip of

Moulded missing parts were adhered

consolidation of the clay, cleaning of

We softened the wax-resin mixture

the palm branch the Saint is holding

with clay soil mixed with addition of

the painted surface, filling of the cracks

with the heated spatula. With the

in her right hand (Fig. 2) and some

different aggregates.

and remodelling of the missing parts.

additional use of a scalpel, it was easily

made of unfired clay and coated with oil colours. The paint layer imitates the surface of glazed terra cotta. of


pieces at the back of the figure. 2.1.2 Survey of the described interventions The rarity of sculptures in clay results

are listed in the following paragraphs. The first example is the intervention








and achieved the satin look of the

to be done in a single step.

The Paraloid B72 was used for the

A damp cotton swab was used to

levelled and modelled. The missing tip

consolidation and bonding in the

eliminate the soiling from the painted

of the palm branch was modelled out in

intervention on a Nodding Figure in


this manner (Fig. 3).There was no need


Remodelling of the missing elements


for additional retouching or coating.

cm), 1933, owned by the Archdiocese of Ljubljana is a plaster cast. The most numerous among the treated sculptures by Gangl are plaster casts. Plaster is an extremely fragile and porous material, highly absorbent and easily soiled. Because of its properties and




storing conditions, a plaster cast can suffer severe damage. 2.2.1 Condition before treatment When The Head of Christ was first examined, it was found to be in overall poor condition. It was broken into four pieces and it had also suffered damage from water (Fig. 4a). There were three holes on the forehead from water dripping, one reached through the entire cast (Fig. 4b). Next to the right side of Christ’s face, there was a cavity, also made by water flowing over the surface. The surface was covered with heavy deposits of dirt, dust and other pollution materials.

from the nature of this material. Clay

The Aquazol 500 was introduced in

of the sculpture was possible because

is a material susceptible to humidity,

the intervention on a Chinese Figure

of the existence of a plaster cast and


and that is why most of the sculptures

in 2001, where it served in various

a bronze version of the same statue.


encompassed reassembly of the

made of clay are fired.

stages of the treatment, also as a




deteriorated areas, cleaning of the

Restorations performed on similar


removed from the clay support by

The Head of Christ (40 x 29.5 x 15

consolidant and filling medium.


Before remodelling we used Paraloid B72 to consolidate the clay and to

2.2.2 Materials and methods CONSERVATION-RESTO-

Ethyl silicate was used for the

a survey shows a very wide range of

consolidation and epoxide resin

In selecting materials for the loss

The following two sculptures share

materials used. Some similar cases with

glue for the bonding a sculpture by

compensation and the filling, the

the motif but they are made of two

the focus on binders and consolidants

Mastroinanni in 2005.

specific, water sensitive nature of clay

different materials.

Martina Vuga

conservation parts,




surface, filling of the cracks and

objects are rarely documented and



make a barrier coat.

Figure 4a (upper) • Alojz Gangl, Head of Christ, plaster cast, before treatment; and 4b (bottom) • Damaged support: holes on the forehead. (© National Gallery of Slovenia, photo: M. Vuga)

remodelling of the missing parts. Some of the dirt was loosely held to the surface and could be mechanically

Filling and colour reintegration in a single step


Figure 6 • Alojz Gangl, Head of Christ, plasticine, before treatment; piece of plaster supporting the plasticine modelling (© National Gallery of Slovenia, photo: M.Vuga)

Figure 5 • Alojz Gangl, Head of Christ, plaster cast, after treatment. (© National Gallery of Slovenia, photo: M.Vuga)

procedure, the

After the sculpture was treated at

The plasticine taken from the back

power vacuum cleaner. Some dirt

reassembled head was flipped and

the back, the face was finally put back

was softened by adding white spirit

could not be mechanically removed.

the wooden board was temporarily

between the plasticine parts on the

and it was used to fill the missing

The plaster was additionally cleaned

removed, so we could reach the

original wooden board. The patches

parts and cracks on the front side of

by using cotton swabs damped in

sculpture from the back.The temporary

of Japan paper were removed.

the sculpture (Fig. 8).

mixture of water and ethanol.

support was then withdrawn. Firstly, we

removed with a soft brush and low


The Paraloid B72 was used as a prior to treatment and also due to for

plasticine, the material that is not very

reattaching and filling followed the

frequent in conservation-restoration

traditional plaster sculpture technology.





support to these parts from the underside enabled reassembling of the sculpture. Putting all the pieces

The broken parts were glued

2.3.1 Condition before treatment

together by means of PVAC emulsion

When the head was first examined

fragments were missing. There was


. Losses to the plaster were

compensated using plaster of Paris (gypsum plaster), modified with the addition of animal glue to slow the setting time. Inpainting of plaster fills was finally executed after the cure by the application of Schminke

prior to treatment, it was found to be in overall poor condition. It was broken into 19 pieces and fragments. Only the low part of the relief had a tight grasp onto the wooden board. A piece of plaster of Paris supported the plasticine modelling underneath

watercolours (Fig. 5).

in the upper part of the head (Fig. 6),

2.3 Conservation-restoration

without the support. As the plasticine

treatment of The Head of Christ,

with its slightly sticky character attracts


and easily catches dust and other dirt

13 cm), 1933, from the Bela Krajina Museum (inv. no. U2) is made of plasticine



modelling material coming from exploitation of petroleum products) on a wooden board. The treatment of this sculpture was more complex due to its condition

Martina Vuga

no need to glue the parts together as they fitted nicely (Fig. 7a). Damaged areas and larger cracks were temporarily covered with a layer of Japanese paper and methylcellulose in water solution.

areas where the plasticine modelling

Figure 8 • Alojz Gangl, Head of Christ, plasticine, after treatment. (© National Gallery of Slovenia, photo: B. Salaj)

was not supported, to enable later filling of the missing plasticine at the front (Fig. 7b). A small amount of the plasticine which did not contribute to the form or stability of the sculpture and represented a certain surplus was removed from the back.

Figure 7a (left) • Alojz Gangl, Head of Christ, plasticine, after reassembling, and 7b (right) • during the making of a plaster support from the backside. (© National Gallery of Slovenia, photo: M.Vuga)

while the facial part was hollow and

The Head of Christ (40 x 28.5 x


would have begun to sag. A temporary

together revealed that only a few



added some plaster at the back of the

consolidant for the support and as a barrier coat.


from the air, the surface was covered with deposits of dirt. 2.3.2 Materials and methods Regarding



treatment the first goal was to reassemble the sculpture. Several parts, e.g. the part of the eyes, did not have any sturdy plaster support, so that during the reassembling they

Filling and colour reintegration in a single step


Similarly, as in St. Agnes’s, also here the filling and the colour reintegration

time consume, it can be sometimes

which would be further complicated

Lorenzo Bernini’s Angels, preparatory

balanced combination of knowledge,

easier and with better results.

by the constituent material, plasticine.

models made of unfired clay have

experience and ingenuity.

Single step method was successfully

attracted my attention since the

applied in this case too.

beginning in 2010 [9]. During the

In a single step procedure of filling and

were done in a single step. As it was already mentioned the

colour reintegration the coloured wax

white spirit solubilizes the components

resin mixture was used in the case of St.

Because we dealt with so different

treatment, different materials to be used

of the plasticine. Its softness also does

Agnes.The mixture is a system without

materials, all requirements for the

were also analysed. A specific cellulose-

not permit the repeated action with

water, colour of the mixture does not

reversibility of the materials and

based impasto was developed and used

cotton swabs, so the surface cleaning

change after hardening and the filling

treatments were not always fulfilled.

for the consolidation, adhesion and

was limited to gentle and careful

does not shrink. Applying and modelling

We tried to follow the principle of

structural reconstructions of unfired

cleaning with water.

method is very easy, working is faster.

re-treatability, keeping the options for

clay sculptures. It was not until 2016

future treatments open, which was by

that the Vatican Museums published

[1] APPELBAUM, Barbara – Conservation

[8] Mavec in bron v kiparstvu. In: Likovni

far more realistic in our case. [15]

a short report on the restoration

treatment methodology. Oxford: Butterworth

odsevi (Kiparstvo), Ljubljana: Zveza kulturnih

Heineman, 2007.

organizacij Slovenije,1990, pp. 106.


The final form, colour and shine

successfully applied and the sculpture

blended well with the original surface.

regained its integrity again (Fig. 8).

In terms of the achieved aesthetics,




the result was very satisfactory in St. 3. RESULTS AND DISCUSSION

appropriate conservation interventions


Agnes’s case.

on sculptures made of unfired clay in

Plaster and other water-based fillings

In less than three years, about

the future, we still hope for additional

The main visual component of an

for porous materials change the

40 sculptures were treated to be

information on the newly developed

(achromatic) sculpture is its form. The

colour when the water evaporates. In

exhibited. The quantity of artworks,


colour of the constituent material

the case of a plaster Head of Christ, the

different constituent materials and

Plaster objects also attract interest

usually determines the colour of the

filling and the colour reintegration in a

the fact the treatments would need

again and are revalued after years of


single step would be quite difficult, as

to be accomplished by the exhibition

having been underestimated. With


the final colour of plaster alters after

deadline were challenging.

the renewed interest, new studies are

sculptures and the effect of the texture

cure so it is very difficult to predict

of the material itself, e.g. porosity of a





[2] BREŠČAK, Mateja – Alojz Gangl, A





Sculptor On His Way to Modernism, Ljubljana:

Fortunatina Cuozzo, conservator restorer

National Gallery of Slovenia, 2010.

from Vatican





[3] Personal communication with Satoshi

Information on exhibitions. Available at: http://

Yamato, Agency for Cultural affairs,Tokyo, Japan


[4] dE VRIES Bouke, The Conservation of a


Vandalised Nodding Figure, Royal Pavillion,


Brighton. In: ICOM Committee for Conservation,

[10] Giovan Lorenzo Bernini e I suoi Mo-

11th triennial meeting in Edinburgh, Scotland,

delli, Il restauro. Available at: http://www.

1996: Preprints, London, James & James (Science


Publishers), 1996, pp. 857-862.



focused on different conservation-

it. Plaster casts can be filled with the

paper were inspired on some similar

restoration procedures for plaster

plaster or satin look of the plasticine

similar materials, but they still need at

documented interventions, but it was

objects today. New cleaning methods

in Unfired Clay: Technical Investigation and


would be harder to achieve by

least some minor retouching.

quite difficult to find similar cases for

have been developed [11]. There is

Conservation Treatment. In V & A Conserva-


Single step procedure was also used

the materials that are quite rare in

some research work going on also on

tion Journal, N. 38, (2001), pp. 10-13.


in the case of the Head of Christ made

sculpture in the first place. We also

proper consolidants [12].


of plasticine.The original material taken

did not always apply or consider the

Dissemination of information on

treatment, the filling and the colour

from the back of the sculpture was

past experience, but it is crucial to

and for appropriate conservation

reintegration can be merged in one.

used to fill minor missing fragments

follow past and the new knowledge

interventions on different materials

Replacing the missing material by a

in front. With the chosen material we

in the conservation-restoration field.

can improve the way conservation

(coloured) fill composed of a similar

also avoided the problematic visual

Unfired clay objects are still a great

interventions are carried out, but

material or even using the original

blending of the original and material



in practical work, decisions are not

one can be an advantage in terms of

added in the restoration process,

The restoration treatment of Giovanni

simple and should be made in a

retouching with a brush and a paint. So in some cases, two (final) steps of


treatment of Bernini’s Angels [10]. For




Martina Vuga




[5] VENTIKOU Metaxia, A Chinese figure

[6] RAVA A., BERTONE V., Problemi di restauro della terra cruda: il caso della scultura


– Use of Rigid Agar Gels for Cleaning Plaster Objects. Saonata: Il Prato, 2008.

di Mastroianni alla Galleria Civica d’Arte. In: Lo

[12] TISLOVA, Renata; ZITKOVA, Petra;

Stato dell’Arte 3: III congresso nazionale IGIIC,

DOUBAL, Jakub. – Consolidation treatments

Nardini Editore, 2006, pp. 208-15

for gypsum plaster models. In: International

[7] HUDOKLIN ŠIMAGA Vera, Praktična





kiparska tehnologija, Navodila za vaje, Ljublja-

multiplication: plaster as an art material.

na: Akademija za likovno umetnost v Ljubljani,

Bruxelles: KIK IRPAA, EPITAAF, 2017, p.16.

1973, p56.

Filling and colour reintegration in a single step


Keywords Albumen; Collodion; layers;


‘Fake Baryta’ support; Photographic material. silver chloride printing-out papers (POP) were devised in which a halogen absorber such as citrate was deliberately added to the emulsion.’[1]. Collodion

It is a three layer prints with binder and Baryta layers; paper fibers are

Albumen photographic prints is a historical


that was created around 1850 (Table 1). It is a two-layer photographic

binder) without Baryta Layer; in these photographic processes paper fibers are visible through binder in highlights, and the photographs have some surface gloss (Figure 1). Main characteristics on the albumen prints are: thin paper support, high ABSTRACT This paper describe the approach and challenging stages in the retouching methods

ethanol/water in different ratios. This

and treatments of albumen and collodion photographic prints associated with a


part of the collections of the Croatian State Archives, which dates from the early

earliest published images in this region

19th century. Photographs where studied using microscopy analysis to assess

and offers a lasting contribution to our

the layers in their painted surfaces, included photographic documentation. The


photographs exhibited image fading, surface scratches, tears, and cracks. They

heritage. Purpose of the research is to

suffered serious mechanical damage - abrasions, scratches, tiny cracks overall and

determine the different approaches to

sometimes missing sections. The materials could not be handled without damage

retouching methods from the different

and conservation treatment was mandatory. The photographs were surface cleaned;


stains were reduced with solvents. Damaged edges were consolidated and tears


mended using Japanese paper and wheat starch paste. For the both prints was used

given their fragile condition, complex

‘fake Baryta’ support. Retouching is made using Schmincke water colors used with

structure and enormous significance.





processes, and


partially or completely obscured


Binder layer is present (egg white

Senior Paper and Photograph Conservator | Croatian State Archives – Zagreb, Croatia | mbagatin@arhiv.hr


prevalent from 1855 to about 1881.


process that contains paper as a base,

Martina Bagatin


in highlights (Table 2). Collodion

Figure 1 • Albumen prints, cross section

prints have a warm or purple image

resolution, good reproduction of

hue; paper fibers are invisible and

fine details, deep rich brown image

sometimes partially visible, no image

tone. Over time or in bad storage

fading, no mirroring. There are two

conditions image will fading and

types of collodion prints: matte

binder will crack. ‘The albumen print,

collodion and glossy collodion positive

which superseded the salted paper

sometimes with gold and platinum

print in the mid-1850s, was a print-

toning. Whether the mat or glossy

out process, and here the albumen

depends on the amount of binder to

may itself act as a scavenger for the

be applied. Mat collodion have less

chlorine. Much later, around the turn

binder while glossy collodion prints

of the century, commercial gelatin/

have more binder applied.



constant innovation

Table 1 • Composition Albumen print SUPPORT






Table 2 • Composition of Collodion print SUPPORT









Figure 2 • Cleaning with solvents

Figure 3 • Mending, using starch paste

Figure 5 • Fake baryta coat and retoruching on the albumen print

1.1 Deteriorations on the

includes the time of creation of

of the photographic material. It was

it must be resistant physically and

approach for the retouch is made

retouch was introduced. It is not


the photographic technique, the

decided first to take the approach

chemically to the chemical processing

using Schmincke water colors, used

easy to achieve a certain tone,

Before selected photographs submitted

dimensions, the historical passage,

and methods in order to reduce and

required to produce the silver image.

with MC (metil cellulose) in water, and

especially after the colour is dry. So

to the Croatian State Archives

and the description of the state of

stabilize the resulting mechanical and

The record obtained should keep

ethanol/water in two different rations:

it is important to do more tests,

suffered several different types of

the photographs, access is made to

chemical damages. The photographs

a long time if properly processed

1:1 and 2:1. Ethanol by its nature and

and determine the right colour.

damages: mechanical and chemical

the identification of photographic

were surface cleaned using wet and

and then stored under optimum

composition has a tendency of drying

This is about monochrome colours

damages. Mechanical damages where

techniques to confirm the process.

dry methods; stains were reduced

conditions.This has been a concern of

and evaporation. The ratio of ethanol

because albumen and collodion are

the secondary support was acid

Identification is made by visual

with solvents, applied locally. In

the industry from the earliest days to

to water depends on how much it

monochromatic. Apart from colour,

and brittle (prints that are mounted

examination to view the surface of the

that case, first step was cleaning.

the present. Some knowledge of the

wants to achieve the speed of drying

it is important to achieve a matte

on acid paperboards), the surface

photographs: microscopic examination

Photographs were dry cleaned from

history of photographic paper making

in the retouch. Sometimes due to the

or glossy effect, with respect to the

scratched, tears, cracks and folded

which contains analysis of elements

dust, and the wet cleaning of glue

will be helpful to the photographic

fragile and damaged structure of the

original photographs. If missing a

along the edge; Chemical damages

(XRF) and organic analysis (ATR-

residues by using the solvents (Figure

conservator in caring for early

photograph, it is necessary to quickly

large part of the photography is

– fading in the lightest image areas;

FTIR). Both examinations consist

2). Soft fabrics were used and soft


dry. Additionally, the composition

necessary to tone the paper that is

they were severely stained from



brushes for dry cleaning and acetone


due to ethanol helps to achieve a

later used as filler. Approach is the

adhesive tapes and other materials.

present in the layers of photographic

and 1: 2 ethanol and water for solvent

Fake Baryta layer was used for the

matte effect on certain photographic

same as in the original preparation of

It was decided that is mandatory

images in order to resolve the possible

cleaning with cotton pads. After

collodion photographic process: A


the photography: preparation of the

that the photographs must be

doubts remaining after the visual

cleaning, a starch paste and Japanese

glossy collodion print is a three-layer

conserved - restored before they are

examination. Unlike XRF analysis,

paper was used to repair the baryta

print comprised of a paper support

stored in storage space, in order to

the FTIR spectrometer determines

layer on the paper support (Figure

with a baryta layer, collodion binder,

preserve the stability of photographic

the photosensitive layer (cellulose,

3). ‘It was recognized early in the

and a silver image. The surface finish

processes-the issue of stability and

albumin, collodion, gelatin ...) and

development of the photographic

longevity. ‘This work includes an

subsequent interventions such as

investigation of methods to restore






support (paper coating and binder/ 3. RESULTS AND DISCUSSION

or not), and the colour is applied (Figure 5). Sometimes is really difficult


to strike the right tone because

ranges from semi-glossy to glossy due

albumen and collodion photographic

photographs regardless of storage

process that there was a relationship

to the thick baryta layer. Baryta layer

processes are made due to provide

conditions tend to change colour

toning, painting or applying different

between the stability of the processed

may be tinted, exhibiting an overall

stability and long –term preservation.

and tone colours. ‘Conservators

photographs produced by historically

coatings on the surface of the

photographic image and that of the

pink, blue, or green tint. A collodion

Since the surface layer of the image

do not have miraculous treatments



photographs. Due to identification,

paper on which it was formed. For

print may also have a glazed surface,

has faded, it had to be fixed –

that reverse the action of time and

conservation treatment photographs

an adequate method of conservation,

this reason, the paper used in printing

resulting in a high-gloss finish. Most

stabilized. The use of methyl cellulose

restore photographs to their original

where studied using microscopy to

restoration and retouching of the

photographs and the material that

glossy collodion prints exhibit a subtle

helps to connect the final layer and

conditions. Misguided efforts to do

assess the layers in their surfaces,

photographs is determined.

comes in contact with them such as

iridescent effect on their surface when

image layer of the photographs,

so can compromise the evidence of

and includes documentation photo

mounting board, negative enclosures,

viewed under fluorescent lighting.

especially if there are residual toning

the age or the pattern of use of an

documentation before, during and

interleaving paper, etc, must be of the

Image tones range from reddish-

and coating, as in some photographs.

object.’ [4]

appropriate content and quality.

brown to purple or violet brown.

It is always essential to use compatible

Photographic paper support must

For the preparation of Fake Baryta,

and reversible materials.

Certain measures are taken on the

be as durable and stable as possible.

it was used: kaolin, barium sulphate

basis of identification and testing to

It cannot adversely affect the silver

and ‘Aquazol 200’ (Figure 4). After

increase the protection and durability

halide emulsion coated upon it and

the preparation of the Fake baryta,

processes’ . [3]


after treatment.

2.1 Cleaning of the photographs and Fake Baryta support

2. MATERIALS AND METHODS After the detail documentation that 108

Figure 4 • Preparing Fake baryta support

Martina Bagatin




3.1. Retouching of the photographs

After the Fake Baryta was prepared,

4. CONCLUSIONS The main goal was to present a gradual approach to conservation

Retouching methods on the albumen and coloddion photographic processes from crotian state archives


and restoration of photographic


material, including the retouching

mechanical damage (is

methods as the main and final act.This

use of cotton gloves); allow the use

is because photographs are complex

of copy for various research; use of

as an object, always composed of

lending at exhibitions. Cool storage

several layers, and the most common

(below 10°C) is recommended, and

cause of deterioration is factors

colder is better unless frequently

such as poor handling and storage

used (frequent and sudden changes

conditions which affect all layers


in temperature and relative humidity

This results in mechanical damage,

could result in physical stress to the

damage to the binder (crack), and

object). Allowable Fluctuation: ±15°C;

surface damage. Also, an additional

±5% RH [9].



improper handling causes mandatory

problem is caused by previous nonprofessional repairs. When everything is taken into account, the retouch is part of the integral process, and the methods vary according to photographic




case, the binding layer (Fake baryta support) is the most sensitive part of the retouching, because without the proper binding layer, color and pigment stability is questionable (over time or in bad storage conditions image will fading). With all this, it is important and almost mandatory to





conditions: temperature control and relative humidity, control of impurities and air pollution and exposure to light. Priority in preserving and protecting




first. Creating a Handbook for a photograph collection it will help a lot; fingerprints can cause chemical 110

Martina Bagatin

REFERENCES [1] WARE, M. Mechanisms of image deterioration




first hundred years, 1840-1940. Ash & Grant Ltd., London. 1978. pp. 102-110.

Science Museum and National Museum of

[6] Conservation of Photographs. Kodak

Photography, Film & Television. London, UK,

Publication No. F-40. Rochester, NY: Eastman

1994, pp.16.

Kodak Company, 1985.

[2] Eastman Kodak Company. Conservation of Photographs. Library of Congress Catalog Card No. 84-80244, 1985, pp.38-40

[7] COPEDE’, M. – La carta e il suo degrado. Firenze : Nardini Editore, 2003. [8] HENDRIKS, Klaus B., KRALL, Rudiger


– Fingerprints on photographs. Topics in

Issues in the Conservation of Photographs.

Photographic Preservation, Volume 5. (1993),

The Getty Conservation Institute, Los Angeles,

pp. 8-13.

2010, pp. 8-15

[9] UPTON, M. S. & PEARSON, C. –

[4] LAVEDRINE, B. Photographs of the Past.

Disaster Planning and Emergency Treatments

The Getty Conservation Institute, Los Angeles,

in Museums, Art Galleries, Libraries, Archives

2009, pp. 302

and Allied Institutions, Canberra. (1978)

[5] COE, Brian – Color Photography: The Nome artigo


Keywords Removal of retouchings; Gamblin Conservation Colors;


Filing; Texture; Retouching; Beva Gesso-P.

1. INTRODUCTION Ecce Homo is a Baroque oil painting on canvas painted by Slovenian painter Leopold Layer. It depicts the standing

Ana Oblak

figure of Jesus Christ wearing a red ^

University of Ljubljana, Academy of Fine Arts and Design; Erjavceva cesta 23, 1000 Ljubljana-SI; E-mail address: anaa.oblak@gmail.com

cloak and a crown of thorns, a motif from the Gospel of John (Fig. 1). The painting is kept in the National Gallery of Slovenia, located in Ljubljana. The painting’s unsatisfactory condition can partially be attributed to previous

ABSTRACT Restoring a painting, which has already been subjected to previous conservation work,

material was suitable for use on

has often proved to be a challenge. According to ethical conservation principles, previous

larger areas, allowing for a thin and

treatment is part of the artwork’s history, which should always be taken into consideration,

layered application. Imitating the

since it reveals what happened with the painting in the past. However, improper treatment

texture of the surrounding paint

in the past can alter the readability of the painting.

layer is key for integration of the

Trying to find the course of minimal intervention, which would sufficiently integrate

fills with the original paint layer and

previously retouched areas with the original paint layer, was one of the problems of

further retouching.

restoring an oil painting from the Late Baroque by a Slovenian painter. The painting showed

The condition of damaged areas and

signs of support and paint damage, which were most pronounced along the edges of the

their treatment, with an emphasis on

painting. The unsuitable retouchings were especially prominent in these areas.

structuring the surface with fills, is

During conservation-restoration treatment, the biggest concern was how to remove the

discussed in this paper. At the end,

discoloured and inappropriately applied materials and which techniques would pose the

practical aspects of the materials

least further stress on the original. After the retouchings and fills were removed, numerous

and techniques are presented and

losses of the paint layer and canvas were found. It was important that the selected filling


Figure 1 • Leopold Layer, Ecce Homo, oil on canvas; 156.5 cm × 92.5 cm. National Gallery of Slovenia, Ljubljana, inv. number 514. Painting before conservation-restoration procedures.


conservation procedures. The original

the painting. They had darkened and

linen canvas was damaged along the

discoloured in the ageing process.

edges of the painting and had been

Additionally, the texture and level of the


retouchings did not match the original

The painting was stretched on a

paint layer. Added materials were

wooden strainer with fixed corner

frequently laid over the original paint

joints and was mounted on the

layer (Fig 2). Some of the retouchings

strainer with nails through the lining

were applied directly to the original

canvas, because the edges of the

linen support (Fig. 3) or on the added

original canvas were missing. The

lining canvas, and some retouched

canvas was thinly woven (7 to 10

areas had an intermediate layer of filling

threads per cm) and not a reliable


carrier for paint layers.

Figure 2 • Filling material and retouching applied over the original paint layer.

Evidently the state of the materials

Lighter and darker stains were

used in previous conservation treatment

noticeable on the added canvas,

was not acceptable. For this reason,

which were assumed to have been

removal of all the obtrusive materials

caused by mould. The existing varnish

and reintegration of lost paint was

was uneven and noticeably darkened.


There were areas of damaged paint layer, some of which had already been


filled in and retouched in the past. Scientific

Figure 3 •  Retouching applied directly to the original linen support.




2.1. Removal of added materials

sequence of paint layers and identified

As mentioned before, the original

the majority of the pigments and

paint layer was over-retouched in

adhesives used. The samples were

some areas. Solubility tests revealed





high sensitivity of the red surfaces

ultraviolet fluorescence


(mainly the red cloak). When testing

Fourier-transform infrared spectroscopy

the possible cleaning agents, removal

(FTIR) and Raman spectroscopy (RS).

of the red pigment cinnabar was

The original and the added materials

detected [1]. This instability presented

differed in composition.

a major threat to the preservation of the original paint layer. These


Ana Oblack

1.1. The state of retouchings

circumstances hindered our attempts

Old retouchings were some of the

to remove materials that were

visually most intrusive elements of

disturbing to the perception of the

Figure 4 • Retouchings removed from canvas and paint layer using different methods.

entire painting. Further effort was therefore required to determine the optimal course of action. The retouched areas were initially studied. The materials proved to be soluble in polar solvents, which also affected the original red paint. Considering the sensibility of the original, an attempt to reduce the polarity with the addition of a nonpolar solvent was made. To prolong the time of action of the solvent on the surface, a gelled mixture was used. This enabled us to apply solvents strictly to the desired areas. With the help of magnifying glasses softened retouchings were carefully removed with a scalpel. Residues of the gel and retouchings had to be removed with solvents in free form [2]. In most cases the areas with removed

Figure 5 • Silicone imprint mould of the paint surface for texturing filled in areas.

the material and adherence to the

2.2. Reintegration of paint losses

paint surface. The fills softened only

Remains of previous conservation

under longer exposure to water in

procedures were carefully removed,

gelled form. Different aqueous gelled

which revealed large areas of missing

systems were tested and had a similar

paint layer and damage of the canvas.

effect.They proved to be suitable only

Tears were mended and inlays added

for areas where fills were present in

into the areas of missing canvas.

thin layers on the original paint layer.

Choosing a suitable filling material

Free water was avoided when removing

was essential. The filler had to be

fills from the canvas, because of the

elastic, allowing thin application and

risk of shrinkage and deformations

good texturing. Imitating the original

of the linen support, which could

texture is key for good integration,

result in damage of the picture layers.

especially in large areas of missing

Therefore further tests with heat

paint layer. Known for its good

were conducted. Using a hot air

flexibility and shaping ability, Beva®

blower the fills were softened and

Gesso-P met our demands, as it

then carefully removed with a scalpel.

seemed particularly suitable for filling

The goal was to safely remove as

larger areas [4].

much of the filling material as possible,

Beva® Gesso-P was applied with a

to reach an appropriate level for a

spatula directly from the can. Gaps

new layer of fills.

were filled in and levelled. Excessive

retouchings revealed a layer of fills,

A hot air blower was also used to

also applied over the paint layer. The

material could easily be removed from

remove larger areas of retouchings

filling material was a sturdy mixture

the paint surface with low aromatic

applied directly to the canvas (Fig.

of silicates, calcium carbonate and oily

hydrocarbon solvents. An imprint

4). Compared to using solvents, this

tempera. Analyses have also shown

mould of the paint surface texture was

method proved to be more efficient.

the presence of vegetable gums,

prepared using Zetaplus™ silicone

There was, however, a possibility of

waxes, starch and pigments [3].

(Fig. 5). The silicone was applied to

damaging the canvas when using a

Attempts were made to remove

the undamaged paint surface, pressed

scalpel. Heat could also soften and

the filling material. Using only a

onto the painting with a roller and

damage the original paint layer. Great

mechanical approach (scalpel) was

left to dry

caution was therefore necessary when

not enough due to the hardness of

patches were made, approximately

using a hot air blower and a scalpel.

15 x 20 cm in size. The air bubbles

. A few 2 mm thick


Dealing with unsuitable retouchings: the steps toward successeful reintegration


Figure 7 • Retouching the painting: finalising with Gamblin Conservation Colors.

Figure 6 • Fills, structured when dry with heat and pressure.

were sometimes problematic, as they

prevented detailed imprinting.

got caught between the surfaces and

After reaching the paint layer

caused disfigurement of the imprint.

level and structure, the colour

The mould was marked in such a

reintegration followed. The base layer

way that its correct orientation was

was done in gouache to achieve a

obvious during use.

suitable hue for the following layers.

The fills were textured before

Brighter and cooler hues were used.

drying completely. The mould was

A 10% Paraloid™ solution in acetone

pressed on to the surface and

was applied only to the retouched

weighed down. It was removed after

areas, to prevent absorption of the

the fills were dry enough to be easily

first varnish layer . [6]

separated from the silicone. In cases

The stretched painting was varnished

where the imprint was not clear, the

with a 20% solution of Laropal® A

fills were textured again when dry

81[4]. The retouched areas were

using heat and pressure (Fig. 6). This

finalised with Gamblin Conservation

was achieved using a heating spatula

Colors, mixed with ethyl lactate (Fig

pressed on to the silicone mould.

7). Retouchings were built gradually in

To achieve sufficient texturing the

tratteggio technique. First the smaller

temperature had to be raised to

lacunas were treated, then the larger

approximately 120 °C.

ones. On the top section of the

to be more fitting, to achieve an

restoration process.

aesthetically suitable match.

In our case, the sensitivity of cinnabar

Retouching is the final stage of

paint and weak, deteriorated woven

reintegrating paint losses. At that

fabric support were recurring issues

point a painting re-establishes its

throughout the entire conservation

character and can be perceived as

procedure, while trying to safely

a whole. Still, colour reintegration is

remove obtrusive elements, added

just one of many steps to achieving



a satisfactory appearance of the filled

treatments. Several methods and

in areas. The choice and preparation

materials were tested to find the

of the filling material are of great

most suitable course of action.

importance. Fills have to match the



While removing retouchings, great

texture of the original paint layer, so

precision was required. The original

that uniform presence is attained. In

red paint layer was susceptible to

our case, satisfactory results were

polar solvents in which the added

achieved when using a silicone

materials dissolved. To soften the

mould for imprinting the texture

over-retouched areas, a mixture of

using a hot spatula. When using

polar and non-polar solvents was

higher temperatures, great caution

used. A hot air blower and a scalpel

is necessary to prevent any damage

were used when removing fills and

to the paint layer. For this reason, the

retouchings. Pemulen® gel was used

described method is more suitable

for softening the fills applied to the

for texturing larger areas.

While the described method was

painting, the biggest missing segment

effective, the silicone mould started to

had to be reconstructed. Larger areas

deform after being used for a longer

of retouchings were also required on

time. We concluded this to be due to

the edges, where new canvas was

its susceptibility to the solvents used


were combined, depending on the


desired condition.

in Beva® Gesso-P. The solution was to simply swap the mould with another and the first mould regained its

Before starting a conservation-

original form. Using an interlayer

restoration treatment a lot of planning

(silicone coated polyester film) wasn’t

is usually done to ensure a smooth

an option due to its thickness, which

workflow. Nevertheless, unforeseen

Ana Oblack

original paint layer. Different methods 4. CONCLUSIONS

area of the painting, to achieve the Inappropriate

one, until the solvents evaporated


issues can disturb the conservation –

The materials









removed, as they were disturbing the

remains of previous conservation

painting’s visual appearance and its

treatments were resolved by balancing

composition. These materials were

preservation of the original paint

substituted with ones we concluded

layer and removal of visually obtrusive

Figure 8 • The painting after conservation treatment.

Dealing with unsuitable retouchings: the steps toward successeful reintegration


elements. As such circumstances require compromise, it is necessary to decide what interventions are acceptable in achieving a better visual appearance of the painting. Although conservators act in order to preserve original materials, in such cases they cannot overlook the aesthetic aspect of the artwork. Regardless of striving to attain minimal interventions, such practice is not realisable in some cases.

REFERENCES [1] NÖLLER, Renate – Cinnabar reviewed: characterization of the red pigment and its reactions’. Studies in Conservation. Vol. 6/2 (2015), p. 79, 82. [2] CREMONESI, Paolo – An approach to cleaning and removal of film-forming materials. Ljubljana: ZVKDS RC, 12. May 2014. [3] KAVKLER, Katja, OBLAK, Ana, Leopold 118

Ana Oblack

Layer, Ecce Homo: Poročilo naravoslovnih

[Accessed 2016] [6] MARQUES, Raquel, CARLYLE, Leslie - Further

preiskav, Ljubljana, 2015. and

Developments on the Use of Beva® Gesso-P InfIlls

Instructions for Use. Available at: Talas online,

and Solutions for Reintegration of a Large Loss. In


III International Meeting on Retouching of Cultural

Beva_gesso.pdf[accessed 2016]

Heritage, Postprints 2015, p. 163-172.





[5] Zetaplus, indurent gel catalyst for c-silicone. Available at: www.zhermack.com. Nome artigo


Keywords Coloured filling, Acrylic dispersion,


they are recognized to be problematic.



Water-and-temperature-sensitive layer, Baroque painting

1.1 Types of losses on the Bergant painting

The painting had suffered from different types of damages, including layer separation. Severe losses, when both the paint

1. INTRODUCTION the most complex colour effects. The Fortunat Bergant, a painter of

colour effect is brought about by an

traditional Baroque technology, applied

optically subtractive mixture of thin

paint layers on a coloured ground with

layers of paint (applied in contrasting

extensive underpainting in cold or

tones as a rule). Within the paint

warm tones. The paint layer consists

surface the thickness and number of

of several layers superimposed one

paint layers vary. The painting has a

upon the other in a manner to achieve

slightly granulated surface.

and ground layers were missing, were most extensive. Those missing parts had been infilled in the past by hide glue-chalk fillers. The old fillers whose structure or level were not suitable were removed (about 60% of filled surface). In some parts of the background

Simona Škorja National Gallery of Slovenia, Puharjeva 9, 1000 Ljubljana, Slovenia; simona_skorja@ng-slo.si

Figure 1 • Different types of losses







showed that the original reddishorange ground was highly sensitive to

The paper presents the case of coloured synthetic fillers used to reduce a number

chosen according to specific damages in

of colour retouching layers on the Baroque canvas painting St Nicholas by Fortunat

the paint layer. Since synthetic fillers are

Bergant (1721–1769). Temperature-sensitive lining and water-sensitive ground

not as malleable as traditional hide glue

paint layers required different approaches to restoration technology, since the

ones, various restoration materials could

restorers in the National Gallery of Slovenia tend to use traditional hide glue fillers.

be used on a single work of art. Coloured

Test samples were made with various synthetic materials mixed with water or

fillings can already imitate the colours

The stated facts were the reason

other organic solvents (e.g. alcohol or acetone), with inert always being Chalk from

of the underpainting and consequently

why different synthetic polymer fillers

Bologna. The selection of added pigments depended on their dimensional response

reduce the number of colour retouching

and high chemical stability. Samples were observed for dimensional response,

were prepared and tested in the

layers. Therefore, the procedure also

absorbency, colour, and surface finish.

reduces water intake when gouache or

studio. Commercially manufactured

Tests on various synthetic fillings confirmed the statement that fillings should be

watercolours are used for inpainting.

water. Furthermore, in the past the painting had been lined with a starchresin mixture which does not allow the use of thermoplastic fillers.

fillers were not subject of testing as

only colour layer separation could be observed (only upper layers of the paint layer were missing). Those shallow damages had been retouched in the past with thick oil paint. A darkened oil retouch which had also had the function of filling was removed. It was necessary to find such a filler whose single application (extremely thin missing layer) would also reproduce the surface texture of the original paint layer.


and chemical stability of added

completely removed also needed

pigments. We definitely have to avoid

further treatment – additional filling

adding hygroscopic pigments, especially

in different level relations. Those

earth pigments containing clay, such

The advantage of some selected

final strength and bond of the filler. [6]

that were preserved were adapted

as Umbras, Siennas, Ochres, etc. and

synthetic materials is that they are

Air bubbles are another disadvantage

through mechanical treatment to

particularly Van Dycke Brown, Natural

soluble in and miscible also with

of synthetic fillers, especially acrylics;

integrate into the original surface.

Iron Oxide and Veronese Green.

polar organic solvents (i.e. acetone,

they can occur during the application

In the process of adding pigments

alcohol), not only in water. On the

and/or drying of the filler and they

to a filler, Laura Fuster-López calls

market they are available as water


In view of the painter’s subtractive

attention to Critical Pigment Volume

dispersions or solids (Aquazol®).

texture of the surface.

manner of applying a paint layer, it

Concentration; the following equation

seemed reasonable to use coloured

can be used:





1.2 Coloured fillings

fillers.This sort of practice is also known from




PVC % = ( V pigment / ( V pigment + V binder)) X 100

case of larger-scale damages. But as noted in literature, evaporation cracks



dispersions is not known in all details;

of acrylic fillers have also shown

undefined types of acrylates, bulking


agents, ammonia or ammoniated

related to environmental changes of




If too much pigment is added it can

compounds can be present as well

temperature and relative humidity.

context, such practice is related to

affect mechanical properties of a filler:

as pigments, preservatives, emulsifying


wax-resin fillers that were mainly used

it decreases stiffness and strength, and

and foaming agents, etc. On the

fillers should be limited only to those

in restoration in the second half of the

on the other hand it increases flexibility.

other hand, the solid linear polyamide

works of art which are exhibited in

previous century.

The surplus of pigments also results

Aquazol® is of known composition,

controlled conditions.

In the process of filling the painting

in lower dimensional response: fillers

with no additional ingredients. [5]

of St. Nicholas the idea was to come

become weak and fragile and tend to

close only to the colours of the

crack, and consequently to fall out.



underpainting or to reproduce mainly the information it contains: the value of

1.3 Isolation of the filler

For this reason the use of acrylic

In our studio practical observation

All selected synthetic materials

tests were made for the following

for fillers can be worked out with

types of fillers: one sample of

polar organic solvents (i.e. acetone,

traditional hide glue filler, three

alcohol), thus

levelling, texturing

samples of acrylic fillers prepared

the light-dark contrast, the value of the

After filling has been completed, an

and removing excess material, even

with water, and two samples prepared

cold-warm contrast. The aim was not

isolation layer should be applied. The

though they were applied as acrylic

with acetone or ethanol, one of them

to completely recreate the quality of

isolation layer creates the boundary

water dispersion.

being linear polyamide.

colour of the underpainting (or even

between the filler and the layers that

the final application of paint), but to


It is advisable that all synthetic

All materials were prepared as 10%

The function of the isolation

fillers be applied in a thin layer on a

solution, with the addition of varied

leave the surface sufficiently “open”

is to prevent absorption of the binder

previously dried up layer. The major

amounts of Chalk of Bologna, Samson

(lightness and coldness of a hue) for

from inpainting and to saturate the

disadvantage is shrinkage caused by

Kamnik as an inner [7], except for the

the application of one or two layers of

porous surface (as pre-preparation

evaporation of water or solvents.

hide glue that was prepared in 7%

the final inpaiting.

for the final varnishing) in the sense of

Shrinkage ranges from a few percent

solution, serving as a reference for its

achieving, as much as possible, uniform

up to 50%, therefore the use of

handling properties.

absorbency all over the surface.

structural support is required in the

A very important issue to be considered is dimensional response

Simona Škorja




sample 1: 7 g rabbit glue, soaked for 24 h 100 ml water 200 g Chalk of Bologna

sample 2:

Practical use and laboratory tests






Table 1 • tested fillers; recipes and photos of samples in daylight and raking light

can be filled with no effect on the

2.1 Tested fillers

Within the Slovenian




10 ml Ares 33 10 ml water 30 g Chalk of Bologna

sample 3: 10 ml Plextol® D 498, Deffner&Johann’s 10 ml water 20 g Chalk of Bologna

sample 4: 10 ml Acrylic Emulsion D 498-M Lascaux 10 ml water 20 g Chalk of Bologna

sample 5: 10 ml Acrylic Emulsion D 498-M Lascaux 10 ml acetone 20 g Chalk of Bologna

sample 6: 10 ml of 10% solution Aquazol® 500 in ethanol 5 g Chalk of Bologna

It is preferable to prepare fillers that

Use of coloured synthetic fillers: the case of St Nicholas, a baroque painting by fortunat bergant


are fluid enough for brush application

although some minor air bubbles can

solution in ethanol. The advantage of

The ratios of the pigments were

in thin layers. Application with a

appear during application in a thick

this material is that is soluble in a wide

decided by test mixing and drying

brush renders possible extraordinary

layer. It dries quite quickly, certain

range of solvents, including water.

of coloured fillers. The process was

The most hygroscopic fillers are the

precision as to where and how much

losses of volume can be observed

The Aquazol® 500 has the highest

repeated several times in the case of

ones made with organic solvents, with

of the filler is applied (it allows control

comparing to hide glue filler.

viscosity of all the tested acrylics, very

“warm pigment selection” before the

the Aquazol® 500 standing out. It

desired colour hue was achieved.

demands substantial isolation before

the Paraloid B-72 for all samples.

over the thickness of application).

Sample 3: the Deffner&Johann’s

similar to hide glue fillers. It requires

In contrast to hide glue fillers, more

Plextol® D 498 has very good

a really small amount of inner, only 5

time is available for corrections

mixing properties, but many air

g, if we want to apply it with a brush.

because their drying time is longer.

bubbles appear which remain on the

However, the Aquazol® , suggested

Two 10% solutions of different

With precise application we can avoid

surface also after drying (undesirable

as a substitute for hide glue fillers,

materials were used for testing

the problem of clouding which often

texture). While still wet, it seems

does not have equally good working

isolation of the filler: organic shellac

For the process of filling the painting

occurs when surplus filler is removed

like a hide glue filler, but after drying

properties, also a certain loss of

in ethanol (traditional use) and the

in question, three different types of

with a cotton pad soaked in a solvent.

significant loss of volume is observed.

volume can be observed.

synthetic Paraloid B-72 in the mixture

acrylic fillers were used after careful

Two layers of the filler were applied

Furthermore, it can be too elastic to

of solvents of acetone and ethanol

consideration: Ares 33 (sample 2),

2.2 Pigments for colouring the fillers

(ratio 1:1). Both solutions were applied

Acrylic Emulsion D 498-M (sample 5),

to sample models with a brush, after


provides a better isolation layer than

be levelled off with a blunt scalpel.

inpainting. 2.3 Tested isolation materials


the first layer was already dry. The

Sample 4: the aqueous mixture of

To colour the fillers two mixtures of

in two layers on all samples of fillers

and Aquazol® 500 (sample 6). The

Lascaux’s Acrylic Emulsion D 498-M

Lascaux’s Acrylic Emulsion D 498-M

pigments were prepared; a cold one

which, however, were not coloured.

fillers were coloured in accordance

mixed with acetone is an exception; it

has the best cohesion of all tested

and a warm one. All selected pigments

It should be taken into account that

with the local tone of underpainting

may become too dense to be applied

acrylic fillers, but some additional

were (pre)wetted in ethanol a day

the addition of pigments may change


easily with a brush (sample 5).

tests should be done. It has a minimal

before the use for achieving better

the porosity and absorbency of the

depending on the area on which they

amount of bubbles when still wet,

mixing properties. The added amount


were applied.

Sample 1: traditionally prepared hide

but they disappear after drying. It

of pigments was always below 0.4 g.

glue filler (as reference) which has

dries slowly, again a significant loss of

excellent working properties, stability

volume can be noticed.



Simple droplet tests of porosity

Most of the fillers were applied with

The “cold pigment selection” was

were made, measuring the time of

a brush in several layers. Application

prepared for the background of

droplet penetration on the isolated

with the brush enabled the imitation

and reversibility [8]. In our case it

Sample 5: the acetone mixture of

the painting. A mixture of synthetic

layer of the filler. The samples were

of the granular structure of the

requires too much water intake while

Lascaux’s Acrylic Emulsion D 498-

Ultramarin dark and Vine black (ratio

photographed every 30 seconds for

original colour layer.Thanks to precise

it is applied and levelled.

M becomes denser than aqueous

ca 1:1) was added to the Ares 33

40 minutes and observed.

application there was no need for

Sample 2: Ares 33, Samson Kamnik

solution, therefore it is more easily

filler (sample 2) and the Aquazol®

(working properties similar to Primal

applied with a spatula. The dried

500 (sample 6).

AC 33, Kremer pigmente as it was

surface becomes rougher than in the

The “warm pigment selection” was

available on the market about 10

case of the aqueous mixture, but it can

prepared for other parts.The following

years ago) requires more inner than

be worked out while the filler is still

pigments were added to the Lascaux’s

other acrylic dispersions, but it is still


Acrylic Emulsion D 498-M (sample 5)

within the safe range. The inner is

Sample 6: Aquazol® 500, Kremer

prepared with acetone: synthetic Iron

miscible well enough with the binder,

pigmente was prepared as 10%

Oxide,Vine black and Ultramarin dark.

Simona Škorja

As expected, the shellac solution

subsequent working on the fillers.

Figure 2 • Tested isolation materials on filler samples, UVF

Figure 3 • D  etail of the filling and inpainting process; losses (1), filling with a brush (2), levelling with blunt scalpel (3), isolation, one layer of guache inpainting (4), mimetic, aquarelle inpainting made of one or two layers with (5)

Use of coloured synthetic fillers: the case of St Nicholas, a baroque painting by fortunat bergant


Minor corrections were necessary at

with a spatula does not allow such

it was only semi-dry, which diminishes

The deepest damages to the support

I would particularly like to point up

mechanical properties of individual

the contact of the filled surface and the

a high degree of precision as the

the possibility of clouding. Another

and the paint layer were filled with

working properties of acrylic filler

fillers for individual types of damages.

original colour layer. The surplus of the

application with a brush does. In this

advantage of coloured fillers is in the

the Aquazol® 500 in several layers.

Ares 33 which can be applied in

When using acrylic materials, we

filler was removed with a blunt scalpel.

case the surplus amount of the filler

fact that the latter phenomenon is

Because structural support was not

extremely thin layers, thinner than in

have to keep in mind, like with


was removed with acetone. Most of

not as pronounced and disruptive as

used, minimal cracks occurred, even

the case of traditional hide glue fillers.

all commercial products, that the

paint layer the Ares 33 (sample

the surplus filler was removed when

in the case of white fillers.

though the filler was applied in thin

The advantage of colouring the fillers

composition is trade secret and can

is that we can re-establish the formal

be changed without notice.Therefore,





2), coloured with a cold tone, was


used. The filler renders possible the

All fillings were isolated with a 20%

unity of the painting, thus the structural

in the case of a new packaging, we

application in extremely thin layers,

solution of shellac, in the case of the

level as well as the aesthetic level,

always have to make previous tests

with no air bubbles occurrence.

Ares 33 two layers sufficed. In the

almost in a single step. A coloured

to check whether the material has

Brushstrokes enabled the recreation

areas of fillings with the Lascaux’s

filler requires minimal inpainting (three

preserved equal working properties

of the appearance and texture of

Acrylic Emulsion D 498-M (sample

layers at the most), which also means

before we use it on a work of art.

the preserved original layer. Poorer

5) three layers of isolation were

that we introduce minimal amount

In any case, a regular, continuous use

mixing of the inner with the binder

necessary here and there. With the

of material which is sensitive to light.

of acrylic fillers, like all other synthetics

was an advantage in our case, since

Aquazol® 500 filler, the isolation was

With the imitation of the colour of

suitable for fillers, requires further

this “fault” perfectly recreated the

applied in five layers at the least.

the underpainting the execution of the

investigation, so careful consideration

granular surface of the original paint

Final colour integration was made

final inpainting is less demanding both

of their use on an individual work of

layer. The use of a filler mixed with

with one layer of gouache colours,

in terms of the material and aesthetics.

art is always necessary.

water did not seem problematic for

followed by individual emphases in

The time of the inpainting execution

it was not applied directly on the

watercolours, in the sense of mimetic

is considerably shortened, which saves

support but on the lower layers of


time and, consequently, reduces the costs of the conservation-restoration

the original paint. This filler also proved to be excellent


A special feature of the present case

for complementary modelling of old fillings where their level had been

The use of synthetic fillers in the

study lies in the fact that the choice of

too shallow or where they had been

works of art that are sensitive to

the filler was dictated by the type of

applied imprecisely.

moisture and temperature is a good

damages to the painting. According

The filler Lascaux’s Acrylic Emulsion

alternative because they enable the


D 498-M, mixed with acetone (sample

preparation, treatment, and possible

industrial producers (Material Safety

5), was applied either with a brush

removal of fillers in polar solvents

Data Sheet), material composition

in the case of minor and shallow

which differ from water. Because

of individual acrylic fillers is rather

damages (in this case minimal amount

of their properties which change

similar, yet unknown in details to the

of acetone was added to facilitate the

with ageing it is advisable that the

users. From this standpoint, it was

works of art are stored in controlled

reasonable to make good use of the


positive working, dimensional and

application) or with a spatula in the case of deeper damages. Application



Simona Škorja

Figure 4 • D  rawing of the used fillers; Aquazol® 500 (sample 6), Ares 33 (sample 2), Lascaux’s D 498 M acetone (sample 5), white colour old, existing fillers.




Use of coloured synthetic fillers: the case of St Nicholas, a baroque painting by fortunat bergant



Dicembre 2012), pp. 42-54.

STONER, Joyce; RUSHFIELD, Rebecca, ed. –

[6] JAIC online; LOEW CRAFT, Meg; A.

The Conservation of Easel Paintings. New

SOLZ, Julie-Commercial viniyl and acyrlic fill

York: Routledge 2012, pp. 586-606.



Available at: http://cool.conservation-us.org/


jaic/articles/jaic37-01-003.html (3 March 2017).

ed. - El Estuco en la restauración de pintura

[7] The composition of Chalk of Bologna,

sobre lienzo. Criterios, materiales y procesos.

Samson Kamnik: 59 % calcium carbonate,

Valencia: Univ. Politécnica de Valencia, 2008.

37,8 % gypsum, 2,4 % anhydride, 0,7 %


flint, 0,1% dolomite. The results were

compensation in paintings: Filling, 11th

obtained by XRF-ThermoFisher Scientific,

Masterclass, Casa-Atelier Vieira da Silva,

Niton XL3t 900S-He. The measurements

Lisboa, 2016.






[4] KNUT, Nicolaus, The restoration of paintings, Cologne: Könemann 1998, pp. 253. [5] DE LUCA, Daphne, BORGIOLI, Leonardo,






Natural Science Faculty, University of Ljubljana, november 2017. [8]




SABATINI, Luigia, VITI, Valentina- Manufatti

materialov, ki se uporabljajo v slikarstvu,

dipinti su support tessile, Reintegrazione

njihova priprava, obdelava in uporaba, prvi del.

delle lacune, Proposta di materiali alternative,

Ljubljana: ALU, 1955, pp.161-206.

Kermes, Anno xxv-Numero 88 (Ottobre-


Simona Škorja

Nome artigo


Keywords Documentation; Graphic recording;

MAPPING LACUNAE FOR RETOUCHING PAINTINGS WITH COMPUTER GRAPHICS SOFTWARE Frederico Henriques | Ana Bailão  | Rui Bordalo  | Agnès Le Gac (4) | Alexandre Gonçalves (5) | Liliana Cardeira (2) | Eduarda Vieira  (1) | António Candeias (3) (1, 2, 3)



1 Universidade Católica Portuguesa/ Escolas das Artes/ CITAR; Rua Diogo Botelho, 1327, 4169-005 Porto; frederico.painting.conservator@gmail.com; evieira@porto.ucp.pt 2 Faculdade de Belas Artes da Universidade de Lisboa/ CIEBA; Largo da Academia Nacional de Belas Artes, 14, 1200-005 Lisboa; ana.bailao@gmail.com; lilianacardeira@gmail.com; 3 Universidade de Évora/ Laboratório HERCULES; Largo Marquês de Marialva, 8, Palácio do Vimioso, 7000-089 Évora; rmbordalo@gmail.com; candeias@uevora.pt 4 Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia, Departamento de Conservação e Restauro & Laboratório de Instrumentação, Engenharia Biomédica e Física da Radiação, Campus da Caparica, 2829-516 Caparica; alg@fct.unl.pt 5 Instituto Superior Técnico/ CERIS; Av. Rovisco Pais, 1049-001 Lisboa; alexandre.goncalves@tecnico.ulisboa.pt

Retouching; Painting; Ortho-image; Blender.

1. INTRODUCTION In conservation and restoration documenting all the actions executed on artworks through a graphic

Figure 1 • Photograph of the portrait of Professor António Vicente Ferreira with a calibration chart.

recording is essential. The same applies in paintings regarding the




exact location of the operations

(GIS), have



carried out on the pictorial surface. In

and can be used in the field of

the condition report, the tear areas,




traces of abrasion, overpaints, fillers,

The aim of this work, based on the

cleaning spot tests, areas of sampling

portrait of Professor António Vicente

(e.g. cross sections) and analysis spots

Ferreira (figure 1) painted by Álvaro

graphic operation occurs prior to the conservation treatment. Blender is an open-source and free software and an all-in-one tool with useful capabilities for documenting cultural heritage. It is a multi-purpose computer program in the areas of 3D

(Raman, XRF, colorimetry, FORS,


Perdigão in 1944 , is to present the

modelling, rendering, simulation, video

among others), for example, should

workflow procedure to support the

editing, game creation, infographics

be recorded

. The registration of

graphic recording of some operations

paint losses is also one of the tasks

in conservation and restoration, in

that should be performed . For the

particular during the retouching phases.

digital registration of losses, several

The painting belongs to the Museum of


computer programs can be used to

Civil Engineering, of the Department

register either vector (e.g. AutoCAD,

of Civil Engineering, Architecture and

The objective of this paper is to present a workflow procedure to support the graphic

Adobe Illustrator, Inkscape, etc.) or

Georesources of Instituto Superior

1.1 Orthophotography or ortho-

recording of the operations performed during the retouching process involved in

raster (e.g. Photoshop, Gimp, etc.)

Técnico, in Lisbon. The method begins


archives. However, a


with a photogrammetric process [7] to

system is necessary for mapping.

acquire an ortho-image of the painting.

Concerning the available types of

In a second phase the work is fully

digital documentation, several non-

performed with Blender, the chosen

conventional applications, such as

3D modelling software. The vector



paintings. In this particular context, an orthophotography of a portrait painted on canvas from a university museum collection was used in Blender, a free and open-source 3D creation software suite. Blender uses an important metric coordination value, provided by the 3D workspace software that allows the areal characterization and numeric identification of each surface loss. The step-by-step procedure adopted to document and map lacunae in this artwork for subsequent retouching, is described.

schemes, scientific illustrations, virtual environments, exporting to several formats (including vector and 3D printing files), and animations, among other capabilities [8].

Ortho-images are well-known in geographic mapping representations. An ortho-image is a digital dataset and can be used in geographic information systems as a layer to support the

Figure 2 • During the characterization of colour and spectral acquisition with FORS.

Figure 4 • Render image produced with Blender software that simulates a virtual gallery.

Figure 5 • Screenshot of Blender workspace during the editing process.

around the painting or in strip lines. To

After processing the data, the result

the 3D model produced by the

creation of other data. They are

frequently in usage in Conservation

1000 nm range. In Blender, 12 points

obtain good results it is necessary to

obtained was a 3D model. On this


essential for producing maps of the

and Restoration or in technical studies,

of FORS readings were mapped on

apply the best practices in photography.

basis, one of the functions of the

necessary to import the OBJ file

Earth’s surface, such as city maps, that

are made with raster drawings, with

the surface layer, registering their

In this project, a tripod, two light

software to generate an ortho-image

format and respective texture (JPG

require the correction of the image

Photoshop® or similar software.

positions and values.

sources with softboxes to provide

could be used. Two types of images

file format). This sort of procedure is

geometry and scale. Such images

However, such scope is limited. To

diffuse light, and a DSRL camera

in orthophotographic view of the

very useful to create virtual scenarios

have uniform scales, correction of

obtain a current and regular recording

NIKON D3200 (24 MP) equipped

painting were acquired: the first in

(figure 4), to produce infographics

the inclination perspective and the

of the pictorial layers and surface, it

with a CMOS sensor and a lens AF-S

low resolution, in JPF file format

schemes or to make animation movies.

effects of parallaxes produced by

is better to create a vectorial record

The method was applied in two main

NIKKOR 18-55 mm were used. All the

(8057x9416 pixels) with 11.4 MB,

However, in the current project on

the optical equipment. Acquiring and

because it allows the interoperability

steps: the first with photogrammetric

images were obtained with the same

and the second in high resolution,

mapping losses, only the JPG image

producing an ortho-image is critical

of the data between software.

procedures to obtain a plane model

value of focal length (23 mm), low

in TIFF file format with 345 MB. For

and 2D file as a plane were needed.





to measure true distances in surfaces

Just like other 3D software, Blender

of the artwork and the second with

ISO value (100) and aperture (F/8).

the next phase of the project, with

The drawing of several gaps was

and mapping the events on the space.

has the ability to create solids, planes

vectorial drawing to build up features

The resolution of the photographs is

Blender software, the JPG file was

made in “edit mode” extruding points

According to principles advanced in

(polygons), points, etc. The workflow

related with the lacunae.

6016x4000 pixels, approximately 12

sufficient to map the lacunae.

around the lacunae area; this resulted

panel paintings

, the same system

presented in this paper started with

was applied in the present case-

polygons under the image of the

study to the pictorial surface. The

pictorial surface (ortho-image).


ortho-image was obtained using a

Blender can also be applied to

in a polygon defined by segments and

MB, and was saved in JPG file format. 2.1 Orthophotography

To produce the ortho-image, a software named Agisoft Photoscan®

The vibration reduction (VR) of the

2.2 Mapping the lacunae with

nodes (figure 5).Then, it was necessary

lens was in switch off mode.

Blender software

to make a polygon with all points. The






The mapping process with the 3D

new element consisted in one object


substantiate technical and analytical


was used. This photogrammetric

photographs acquisition was similar

modelling software Blender (v. 2.78)

with a unique ID (characterized as loss

consists of making measurements

studies of Cultural Heritage assets.

software is widely used to produce

to what would be used for aerial

began with the upload of the ortho-

unit). All drawn losses could then be

from photographs (multiple records).

In this case study, Fiber Optics

3D models and also to acquire

photogrammetry, scanning the surface

image in the project. Then, the object

organized in groups or in one group

Reflectance Spectra (FORS) (figure

terrain information with unmanned

in strip lines, with a high overlapping

was oriented in X, Y, Z axes, and the

with a hierarchy and organization

2) was used. This equipment obtains

aerial vehicles (UAV).

of photographs, between 60% and

map scale was updated to display



70%.The set of records (57 positions)

proper distances at the centimetre scale.



1.1 Mapping lacunae with Blender


the spectral information on a given

should always be done with vectorial

spot of the painting concerning its

works with the upload of a set of

is an aggregate of organized images in


reflectance properties in the 300 to

photographs acquired in sequence

a mosaic (figure 3).



Figure 3 • Screenshot of the photogrammetric project in Agisoft Photoscan® software with the photographs taken in mosaic grid.

lacunae Some

in graphic




Frederico Henriques | Ana Bailão | Rui Bordalo | Agnès Le Gac | Alexandre Gonçalves | Liliana Cardeira | Eduarda Vieira | António Candeias

The cartography was made after the manual work of editing all polygons

If the option consists in uploading

(losses). The final output was not

Mapping lacunae for retouching paintings. With computer graphics software


Figure 6 •  Cartographic map of lacunae and vulnerability areas of the pictorial surface.

Figure 7 • During color retouching with “texture painting” clone tool.

It is worth emphasizing the added

It is also necessary to refer the

value of digital color retouching, for its

large potential of virtual scenarios


absolute reversibility and its benefit as

and infographic strategies with 3D

calculation, Blender as a tool proves also

an independent and didactic support

modelling techniques. The tool can

essential because it allows an objective,

that, together with the real painting,

also be used to communicate in

(figure 6).

reliable, reproducible, and extremely

can promote its better understanding

Heritage Documentation, using 3D

fast and friendly quantitative assessment.

(figure 7and 8).

modelling techniques of the industry


This type of evaluation is central to both

only a map of losses, but also a map of original and non-original paint. Moreover, such a cartography resulted also in a map of risk displaying the most vulnerable areas of the painting

This workflow with an ortho-image, generated with a photogrammetric software, and vectorial editing of lacunae with a computer graphics software




identify all gaps in the painting. Each lacuna, after the manual drawing, acquired an identification number to match a lacunae unit. The total number of lacunae in this painting is 22 and there are14 regions with abrasion. Besides a straightforward localization of the gaps on the whole surface, according to the adopted color scheme (lacunae of red color over a plane grey ground), the cartographic map also allowed to


Figure 8 • Main region of the painting after the color retouching process (left side) and “UV map” and respective texture of the 3D object (photogrammetric model) (right side).

quantify the percentage of losses, which amounts to 1.9%. By



After generating a cartographic

diagnosis and intervention because it



the documentation techniques and

provides a secure expertise as to the

project can always be adjusted or

procedures in Cultural Heritage meet

degree of authenticity of the artwork;

consolidated with more data. This

effectively the computer graphics

it establishes precisely the defective

is fundamental to understand the

knowledge area. Here, a simple

chromatic areas, their shape and

scope of 3D projects in Cultural

presentation of a virtual scenario was

distribution; it contributes to the cost

Heritage and of the Conservation

made with the mapping of analysis

estimation involved in the inpainting

and Restoration technical studies. As

spots (FORS) on the museum

process, be it digital or real in the work

an example, an online 3D model for

painting (figure 10).


virtual visualization was also produced






lacunae, each

of films and games. This means that

in this project. The virtual platform Skecthfab® was used to this end

This kind of operation is widely applied

The platform hosts a 3D repository

The use of current computer

with photo-editing software, with 2D

and a collection of some 3D museum

graphics (CG) tools in Cultural

images. It can also be made directly

objects. The analyzed painting is

Heritage is starting to get attention

in the 3D model, in the imported

one of them, thereby becoming a

from the community of conservation

photogrammetric object or even in the

powerful public awareness medium

and restoration professionals. It is

2D image. The operation is made with

regarding Cultural Heritage concerns

important to refer that CG software

the well-known clone tool (figure 7).


Frederico Henriques | Ana Bailão | Rui Bordalo | Agnès Le Gac | Alexandre Gonçalves | Liliana Cardeira | Eduarda Vieira | António Candeias

systems, but a possibility to promote

it is critical to create comprehensive

infographic illustrations, like those

databases for the data associated with

of cartographic products, for three-

each artwork, enabling the storage

dimensional objects. About the GIS

of all information from conditioning

software and CG software available

reports, conservation and restoration

nowadays, it is possible to work


with standard files and export files

analytical reports, as well as the

to ensure the interoperability within

graphical documentation produced

project data.

for the object. Noteworthy is also the



In the future, with the massive

potential of graphical documentation

amount of information acquired in

to produce and register spatial analysis

conservation-restoration operations,

and risk maps of the artworks.


offers is, in fact, the virtual retouching.

(figure 9).

Figure 9 • An overview of 3D model painting useful for on-line visualisation in the Sketchfab® platform and repository of museum objects.



is not a substitute for GIS or CAD

Figure 10 • Virtual scenario made with Blender. The image informs about the location of analysis spots with FORS system.

Mapping lacunae for retouching paintings. With computer graphics software


REFERENCES [1] STUART, Barbara H. - Analytical Techniques in Materials Conservation. Wiley, 2007. [2]

[7] HISTORIC ENGLAND – Photogrametric SCHMID,




Applications for Cultural Heritage. Guidance for

Documentation Systems in Mural Paintings

Good Practice. Swindon: Historic England, 2017.

Conservation (GRADOC) Roma: ICCROM,

[8] Blender. Home of the Blender Project.

2000. [3] FUENTES PORTO, Alba - Los Sistemas

Available at: https://www.blender.org/ [31 January 2017].

de Información Geográfica aplicados al estu-

[9] BAILÃO, Ana; HENRIQUES, Frederi-

dio de las superficies pictóricas. Valencia: Uni-

co; CABRAL, Madalena; GONÇALVES, Ale-

versidad Politécnica de Valencia. Dissertação

xandre – Primeiros passos de maturidade a

de Mestrado, 2010.

caminho da reintegração cromática diferen-

[4] HENRIQUES, Frederico - Metodologias de Documentação e Análise Espacial em

ciada em pintura de cavalete em Portugal. Ge-Conservación. 1 (2010), pp. 127-141.

Conservação de Pintura. Porto: Universidade

[10] Agisoft Photoscan. Available at:

Católica Portuguesa, 2012. PhD thesis.

http://www.agisoft.com/[30 November 2017]

[5] BAILÃO, Ana; HENRIQUES, Frederico; MENDES, Susana; GONÇALVES, Alexandre - Estudo para a caracterização espacial e bidimensional das lacunas no processo de reintegração cromática da pintura “A Circuncisão do Menino Jesus”. Ge-Conservación. 10

[11] Sketchfab. Publish, share, and discover 3D content on web, mobile, AR, and VR. Available



November 2017] [12] The 3D model of Engineer António Vicente Ferreira painting (Sketchfab).

ACKNOWLEDGEMENTS We are grateful to the Museum of Civil Engineering, of the Department of Civil Engineering, Architecture and Georesources of Instituto Superior Técnico, in Lisbon, for providing access to the painting used in this study and also to its Director, Prof.

Availlable at:

Ana Tomé (PhD Arch). This project had the

[6] PAMPLONA, Fernando – Álvaro Per-


financial support of Fundação para a Ciência

digão. In Dicionário de Pintores e Escultores

454b8cb88ae0b64c195e2b [30 November

e a Tecnologia (FCT) through a Post-Doctoral

Portugueses. Barcelos: Livraria Civilização Edi-


Fellowship (SFRH/BPD/99163/2013).

(2016), pp. 6-19.


tora, 2000, Volume IV, p. 288.

Frederico Henriques | Ana Bailão | Rui Bordalo | Agnès Le Gac | Alexandre Gonçalves | Liliana Cardeira | Eduarda Vieira | António Candeias

Nome artigo


Keywords Colour reintegration, Gold reintegration,


Tridimensional Works of art,

extensively regilded (third layer of gold) when moved from the chapel to

Attic vases, Retouching techniques.

the presbytery of the cathedral, in the second half of the sixteenth century. We also found, dating of nineteenth century, a layer of Prussian blue and artificial ultramarine blue, layered on


bare areas of the reliefs. Last

year, we




conservative intervention on some marble high reliefs and statues from the Cathedral of Orte, near Rome . [1]

These artworks were part of the altar dossal of the Saint Valery Chapel, built during the first years of the sixteenth century


with marbles, reused

S. Pannuzi(1) | M. Valenzuela(2) | D. Montemaggiori(3) | G. Galanti(4)

probably from the Antiquity, belonging

1 Archaeology, MIBACT-ISCR; 2 Restorer, MIBACT-ISCR; 3 Restorer, dariamonti libero.it; 4 Restorer, giorgiagalanti gmail.com

was moved from a chapel to the main

to two different altars [3]. In the second half of the sixteenth century this dossal altar in the cathedral presbytery. In the eighteenth century the altar dossal was dismembered, and each part had then a different reuse with new polychrome covering [4]. Now most of


the underlying one.The altar was then

Polychrome sculpture,

the pieces are shown at the Diocesan

gilding, some have only a few traces,

Our cleaning intervention didnâ&#x20AC;&#x2122;t

and some have none. If the altar could

remove any colour at all and any

one day be rebuilt at the end of our

gold layer, even if some of them were

intervention, our aim will be to balance

identified as non-original. We decided

those differences.

to keep the more recent and extended

We started working on three

gold layer, because it has an important

sculptures that show some extended

historical weight, as well as the traces

areas of beautiful and well-preserved

of different non-original blues which

gilding with some evident losses.

give us an idea, although pale, of what

Decision had to be taken: reintegrate

probably the altar was like.

or not the gold? Which materials to use,

We thought that retouching the gold

pure gold, micas, bare watercolours?

losses on stone polychromies should

Which technique to choose:


not be too different from retouching

identifiable or a mimetic one? Which

similar losses on other materials. For

alternatives ways we had?

a correct methodology we took

This contribution will illustrate

inspiration from first treatments

different methodological and technical

adopted in ISCR on bi-dimensional

proposals about retouching.

panel paintings [6,7] using the tratteggio technique. The same methodology as

Museum of Orte. The Italian Institute for the Conservation and Restoration (ISCR) carried out a conservative intervention on some marble high reliefs and statues from the Cathedral of Orte near Rome. Some pieces have extended polychromy and gilding, some have a few traces, and some have none. Our goal was how to balance those differences and also how to harmonize the original areas with the already repainted and regilded ones we decided to keep. For a correct methodology we took inspiration

In the original phase, when exhibited in the chapel, the altar was painted and partially gilded. When moved to the main altar it was fully and extensively re-gilded. Presently due to the different

from recent treatments adopted in ISCR on different materials as terracotta and

conservation conditions some pieces

wood sculptures and greek and roman pottery.

have extended polychromies and


been used recently on tridimensional gilded and/or painted artworks as

The examined stratigraphic samples [5]

show a first original layer with gold

cold painted terracotta sculptures , wood sculptures



and greek

leaf on decorative reliefs, smalt blue

and roman vases. Being the use of

and azurite on flat grounds, and a

tratteggio unsatisfactorily applied on

second gilding layer coinciding with

tridimensional objects, quite recently

in ISCR we are trying to unify the


applied in a mimetic way (see Fig.1).

was very thin. We put directly on

technique of recognizable retouching

After cleaning and removing the old

reintegration in tiny areas of the gold

the surface of the stone a coating

on all kind of tridimensional objects,

retouchings and fillings we decided to

leaf with Scminke aquarelle mica gold

of mica gold. The perfect matching



reintegrate the gold losses. We first

but treated differently larger lacunas.

of the colour was reached using

tratteggio but with the puntinato.

filled the losses with a gesso ground,

At the beginning we decided not

watercolours that were applied with

This technique was first introduced

and then we covered the surface

to reintegrate the larger areas. The

the puntinato technique on top of

at ISCR in the restoration of wooden

with a coating of even, uniform gold

disturbing visual interferences on the

the gold coating, in order to make

polychrome sculpture in the early

mica based watercolour (Schminke).

surface of the bare stone, appearing

them be recognizable at close range.

’90, following the methodology so

When dried we applied watercolours

through the losses, were treated with

It is premature to assert which will

well illustrated by Paolo and Laura

with the puntinato method in order

glaze watercolours to re-establish the

be the final solution for the retouching

Mora with Paul Philippot

to catch the perfect tone and make

uniformity of the surface, receding in

that will be adopted.





for wall

paintings. Examples of puntinato:

recognizable the area that had been reintegrated (see Fig.2).

Figure 2 • Detail of fig.1. A: lacuna retouched imitating the red bole; B: same lacuna with gold retouching, detail of the puntinato.

space. Progressively, we reached the

We made and used drawings in

be easily identified, using the same

light watercolours glazes to provide the

decision to reintegrate the gold losses

order to develop some hypothesis

1.The terracotta Nativity, by Saturnino

2. The Apulean Amphoras, from the

puntinato technique (see Figure 3).

uniformity to the surface that showed

in the Saint Leonard robe because

of the ancient polycromy, based

Gatti (Sixteen century), Santa Maria del

National Archaeological Museum of

“The result is a reconstruction which

wears of patina and colour.The gold, very

they are in a very prominent position,

on the traces of the original layers

Ponte, L’Aquila. Composed of three

Naples. These objects had no gold

is invisible at the normal viewing

well preserved, had to be retouched to

and because of their extension, not

we founded. We documented the

elements modelled and cold painted,

colours, but they are interesting

distance but easily recognizable at

reconstruct the losses.

too vast. There was no need of a

different phases and the many

damaged by the earthquake of 2009.


close range”

The lacunas in the gold mantels were

. These words, used

In the past at the IsCR, losses of gold

ground because the layer of the

changes the coloured areas had

reintegrate limited losses by modelling

to describe the tratteggio technique,

leaf had first been retouched with bare

original gold leaf around the lacunas

during the time. This restitution was

in the past retouched as losses of the

and drawing what can surely be

perfectly explain the puntinato.

watercolours which could not match

ground, with the colour of the bolo layer

reconstructed in a way which can





Figure 1 • Nativity by Saturnino Gatti (Sixteen century) Santa Maria del Ponte (L’Aquila), a detail of St. Joseph, terracotta and cold painting. A: Losses of the paint layer previously retouched imitating the red bole (before); B: Same losses with gold retouching, watercolours and mica (after).


In our case study we did

S.Pannuzi | M.Valenzuela | D.Montemaggiori | G.Galanti


the shine of gold. Shell gold was then RESULTS AND DISCUSSION

introduced and applied on watercolours

Figure 3 • Naples, National Archaeological Museum, Apulian Amphora. A: reconstruction shape; B: after puntinato retouching.

base with the tratteggio technique. But Presently we had been working only

the result was still dull because the

on three elements of the altar, and

vertical lines come out heavy and thick.

we will be working very soon on the

We tried then to apply the gold leaf first,

other four pieces: it’s only considering

with the guazzo technique, and execute

all the pieces together that we will

the tratteggio with watercolours on

be able to verify the options about

top: the effect was finally very satisfying.

the aesthetic issues and the final

Similarly, applying a layer of uniform, even


mica gold colour and using on top the

Basically, we had to deal with two

watercolours to execute the tratteggio

colours, the pale fade blue and the shiny

or the puntinato was also working well

compact gold areas. We did a very

with the advantage of being far less

light retouching in the blue area, using


Gold and polychromy on stone: a proposal of retouching methodology that can apply on all tridimensional artworks


intended to help the study of the sculptures. Possibly if the altar will not be reconstructed in the Museum, we suggest realizing a small copy of the monument using 3D printer with the reconstruction of the polychromies based on the most assured hypothesis we made.That will help the fruition of the sculptures. REFERENCE CONCLUSION

[1] ANSELMI, Salvatore Enrico Sculture lapidee e lignee. In ANSELMI, Salvatore Enrico;

restauro. Palermo: Regione siciliana, 2008.

This specific case gave us the

PRINCIPI Lorenzo ed. Il museo d arte sacra

[8] HUBER, Helisabeth; PRUNAS, Maria

opportunity to check on polychrome

di Orte. Perugia: Nuova Linotypia 2000, 2013,

Elisabetta; VALENZUELA, Marisol; CATALLI,

pp.50 53






methodology that can be the same for all the tridimensional art crafts and can easily be applied.

[2] LEONCINI, Lando La Fabrica d Orta Orte manuscript XVII century

Elena; Tecniche di esecuzione e intervento di restauro, in MIRACOLA, Patrizia, ed. Il restauro

[3] NEGRI ARNOLDI, Francesco I marmi

di due opere in terracotta dipinta il presepe

quattrocenteschi del Museo Diocesano di Orte.

di santa Maria del Ponte e la Madonna di

In MADDALO, Silvia ed. Tesori di Orte. Man-

Collemaggio. Roma: Gangemi Editore, 2015,

ziana (RM) :Vecchierelli Editore, 1998, pp.73 85.

pp. 21-42

[4] A nameless drawing dated 1723 shows

[9] VALENZUELA, Marisol; CONTI, Laura; TOC-

all these marbles on the main altar before

CI, Laura; L’intervento di restauro sulla scultura

its destruction ANSELMI, Salvatore Enrico

lignea policroma del XIII sec. Madonna con

Commitenze ad Orte in età barocca. Cultu-

Bambino conservata presso la Pinacoteca civica

ra gesuita e influenza pozziana. Gli Alberti e I

di Fabriano: problemi di presentazione estetica,

Nuzzi. Roma: Argos, 2006, pp.126 131

in GIUBBINI, Giovanna ed. -150 anni della Pi-

[5] Results will be soon published in Bollettino ICR Roma

nacoteca di Fabriano. Milano: Affinità Elettive, 2014, pp. 95-106

[6] MORA, Costanza; PROVINCIALI, Beatri-

[10] MORA, Paolo e Laura, PHILIPPOT Paul

ce; SOAVI, Albertina - Antonello nel percorso

Problems of presentation, treatment of losses

delle opere restaurate dall’Istituto Centrale

in Conservation of wall paintings. London:

per il Restauro: dall’Ecce Homo del collegio

Butterworths 1984, pp.304 306.

Alberoni alle tavole degli Uffizi, in Kermes

[11] Bolo is the ground (Armenian bole,

Dossier 19 (aprile / giugno 2006), Firenze:

usually orange reddish colored) used to apply

Nardini 2006, pp. 50-66

the gold leaf (guazzo technique). It’s clay

[7] AA.VV., BASILE, Giuseppe, GRECO Vera 142

ed. -Annunciazione Antonello da Messina: il

S.Pannuzi | M.Valenzuela | D.Montemaggiori | G.Galanti

component makes possible to burnish it. Nome artigo


Keywords Sculpture; Gilding; Inpainting;


Loss compensation; personal experience, his training


and his influences. By means of


concrete examples, we will see how in practice the different degrees of acceptance of losses and the values accorded to gilding lead to a wide


range of solutions and a multitude of Dealing

Emmanuelle Mercier | Erika Benati Rabelo





reintegration of losses on gilded surfaces on polychrome wooden

Institut Royal du Patrimoine Artistique. Parc du Cinquantenaire 1, B-1000 Bruxelles emmanuelle.mercier@kikirpa.be, erika.rabeloé@kikirpa.be

sculpture requires to first define the terms of the title. First of all, what value do losses on a wooden sculpture represent? In 1970, Paul Philippot distinguished between an absolute lacuna on a 2D image and a relative lacuna on a 3D object. He explained that “… contrary to what happens in a painting, the colour of the polychromy should not depict the object but rather qualify


the volume already provided by the sculpture”[1] . In other words, contrary

retouching techniques.

to an easel or a mural painting, the

1.1 When the object was completely

polychromy represents or mimics


above all a material, a texture and

Since the Middle Age, polychrome

less often, figurative depictions. This

wooden sculptures were entirely

difference significantly influences the

repainted and regilded when they

viewer’s perception and acceptance

were damaged, or simply to bring them

of a damaged object.

up to date. In Belgium, this tradition

Secondly: what role does gilding play in

continued without interruption till

a polychromy? What value is attributed

the end of the nineteenth century.

to it? As a metallic leaf applied on top

During the period of the neogothic

of a layer of bolus, can we distinguish it

movement, the restoration aimed at

from the pictorial layer which contains

returning the object to a hypothetical

the artist’s stamp, his brushstroke?





When it is deteriorated by the

reproducing the gleam of the gold.

passing of time, can we simply

The intervention makes the sculpture

replace it without betraying the

look like it had just come out of the

In the restoration of wooden sculpture, the application of a new gilding traditionally

be appreciated, a gilding on a wooden

appeared as the best option to handle the problem of wear damage and gaps in

sculpture doesn’t necessarily have to be

a gilded surface. This practice, which continues up to this day, however, rarely

complete. When inpainting is needed,

authenticity of the work of art? Or

artist’s workshop. However, already

reproduces the quality and technique of the original: colour of gold, colour of

the use of pigments in various mediums

on the contrary, should we respect its

at this time, the secretary of the

the mordant, water or oil gilding, matt or burnished surface, presence of glaze…

makes it possible to carry out surface

Alternatives were found in the use of metal powder such as bronze powder, which


material authenticity?

Royal Commission for Monuments,

oxidizes rapidly, and a wide range of micas to reproduce the glittering metallic


surface in different colours. Alternative options that do not imply the use of metallic

continuity of the gilded volume ensuring

powder are favoured by the authors.

the distinctness and reversibility of the

Following the concept of a ‘relative gap’ in sculpture formulated by Paul Philippot


(1970) [1], the different case studies presented in this paper illustrate that to




and the

allows optical








international ethical guidelines, our

1891), complained about the habit

criteria for the decision making

of stripping altarpieces to repaint

rest upon socio-cultural values, to

and regild, describing the practice as

which we should add the restorer’s


]. This pioneer wished


for restorers to apply the principle of

the technique of the original. In the

“the less you do, the better” (1873).

framework of certain restoration

Nowadays, even if the practice is

sites, when gilding on mordant –

not quite extinct, it is at least not

which works easier and faster – is

approved by the public authorities.

applied to an ensemble without

However, the following question

bearing this “sfumature” in mind, the

is still posed to us, restorers, many

result is often

times: “And are you going to regild or

indeed kitsch [5].

repaint it?” Indeed, the general public

In the past, partial gilding was also

does not entirely understand the

used to cover losses on sculptures.

difference between the treatment

During the restoration of the Opitter

reserved nowadays for sculptures

altarpiece in 1875, the restorer did

and for historical interiors.

not entirely repaint and regild the

In the 1990s, some rooms in the royal

retable as was usually done, but simply

palace of Brussels were studied prior

regilded the losses imitating the painted

to their restoration.The study revealed

decorative motives and the sgraffito

the high quality of the original gilding,

on gold of the original polychromy.

and in particular rich variations in the

This kind of treatment was applied

tonality of the gold leaf .These subtle

to the Kerevot altarpiece in France








highly in


with the same techniques by a team


of professional gilders under the

intervention is clearly visible but not

supervision of restorers.

particularly harmonious.


1970s. This

Even today, in the restoration of

Alternatives were also found in the

historical interiors, the application

use of metal bronze powder, which

of a new gilding appears to be the

oxidizes rapidly. It is often a real

best option to tackle the problem of

challenge for conservators to eliminate

wear damage and losses on gilded

this material without damaging the

decorative elements. In France, a

gilding underneath. In 1983, it took a

chemical marker has been developed

villager two hours to apply a bronze

by the firm Dauvet in partnership

powder on the garment of the Virgin

with C2RMF to ensure the traceability

in the Church of St. Bavo in Erpe-Mere

of gold leaf used within the field of

(13th century). It took us two years to


eliminate it mechanically and make the

. This practice, however,


rarely reproduces the quality and


exceedingly heavy,

Nome artigo

underlying gilding visible again.

1.2 Minimal intervention

At the IRPA, when treating losses, we do not differentiate between gilded and painted areas – the polychromy is a unity of both. Contrary to the previous examples, we attempt to tone down the visibility of the damaged area and improve comprehension of the sculpture, while emphasizing its historical value. This implies accepting the wear and losses on the gilded surfaces of sculptures and altarpieces and to treat them with the same criteria that are applied to the pictorial layer in compliance with ethical guidelines,



removability, etc. As a very general rule, the degree of acceptance of a gap by the general public is proportional to the age of the object. Hence the importance of justifying our choices and explaining the reasons behind the degree of intervention (or non-intervention). We are well aware that this approach is not adopted everywhere. In the decision making process, the choice of both the degree of intervention and the retouching technique involve distinguishing the different types of losses encountered: the wear of the gilded surface; loss of the metal leaf revealing the mordant, the bolus, the white preparation, or the bare wood; loss revealing the

juxtaposition of different surfaces, etc… The following examples will be classified depending on these different kinds of degradation.

1. 2. 2 Lacunae with visible wormeaten wood surrounded by gilding A Dormition of the Virgin (15011550)




workshop in Italy (Museum of Fine 1.2.1 Lacunae with visible wood surrounded by gilding The Virgin from Marche-les-Dames

Ar ts, Gent) suffered damage from wood-boring numerous



gaps. The


(TreMa Museum in Namur, ca. 1260)

carried out did not involve any

illustrates a kind of treatment usually


adopted at the IRPA,and which consists

of carefully selected insect galleries

of leaving the bare wood visible in the

and holes, helped to regain a

lacunae. It is presumed that viewers

cer tain structural continuity of the

are able to mentally reconstruct the

reliefs and shift attention away

missing part. In order to help them

from damages. The intervention

in this task, it is sometimes necessary

consisted first in making the back

to give the wooden surface a more

panel look more homogeneous

homogeneous appearance.

and flat in order to function as a


. In fact, the filling in

The altarpiece of Bouvignes (ca.1555)

background again. Secondly, fillings

treated in 1992 is another example of

made it possible to re-establish a

this option (fig 01 and 02). The bare

cer tain fluidity in the lines of the

wood is clearly distinguishable from

architectural elements.

the remains of polychromy. It can

The choice of the gaps to be filled in,

be compared to a neutral tone with

often depends on the conservator’s

the advantage however of being an

own sensibility. Therefore, it is

inherent element of the sculpture, an

impor tant to determine beforehand

intrinsic part of it. From an aesthetical

those losses that are most disturbing

point of view, the tonality of the wood

to the perception of the form and

is similar to that of the gilded parts,

the composition, in order to make

especially as the wood is oak. In the

our intervention as logical and

end, this kind of minimalist intervention

justified as possible. Sketches and

enables the reconstruction of the

digital simulations were made as a

optical continuity of the sculpture’s

suppor t for the discussion during

volume while integrating the gilded

the decision making process which

areas still present (fig 01 and 02)

was carried out collegially.

Fig 01 • The altarpiece of Bouvignes 1555 (ca), after treatment

Fig 02 • The altarpiece of Bouvignes 1555 (ca), after treatment.

“The golden stain of time”: the inpainting of gildings on wooden sculpture



on conservation ethics. For instance,

or restoring, the dilemmas of heritage”

tone. In the zones that were worn due

a painting the lines of retouching are

revealing the bare wood and losses

multiplying retouching options on the

deep gaps in relief areas where there

(1893), where poor restorations let him

to the manipulations of the statue,

applied vertically while in the case of

revealing the white preparation

same object at the risk of seriously

is a risk of scraping off the gilding

distinguish between the old and the

such as dressing it or walking it in the

a sculpture’s polychromy, the restorer

surrounded by gilding.

disturbing the viewer’s perception of

during handling, or gaps that could

new, whereas good restorations plunge

procession, and showed the red bolus,

would be inclined to adapt the direction

both the form and gilded surface.

also become “dirt holes”.

him into such perplexity of judgement

the tone was adapted to the bolus.

of the lines to the modelling of the

that the pleasure of contemplating the

This was done to conserve the traces

reliefs, such as drapery folds. This is

monument vanishes .

of the material history that are linked

indeed what Ornella Casatta suggested:

to the sculpture’s cult (procession and

“il tratteggio avrà un andamento che

dressing of the sculpture).

dovrà tenere conto dei valori plastici





When losses revealing the bare




wood show a little white chalk or

Definitely secondary in the context

gesso ground, it is often sufficient to

1.2.4 Losses revealing the bare

of a museum, aesthetic criteria become

tone down the white preparation in

wood and losses revealing the white

important for religious sculptures that

order to move these areas into the

preparation surrounded by red bolus

are still objects of devotion.

background. It corresponds to what

A Saint Jacob (ca. 1350) from the

The fillings are usually flat in order

reasons, retouching with tiny dots

S. Bergeon considered as minimal

church of Sainte-Waudru, Mons, was

to make the reintegration appear

or ‘pointillism’ is the method that is

reintegration which, according to

treated in 1998. The gold leaf was

brighter and match the smooth and

nowadays generally applied at IRPA as

her, consists of “… treating the visual

severely deteriorated, revealing large

glittering metallic surface of the gilding.

illustrated by the treatment of a Virgin

emergence of areas that are too

areas of preparation with remains of

Once the mastic is applied, restorers

known as Our Lady of St. Séverin in the

bright or irregularities in the support,

red bolus. Here, one could state that

have various options for retouching.

St.-Martin Church in Liège (ca. 1520)

the preparation, or the coating in

the deteriorated gilding, deprived of its

The Virgin with Child called “Causa

in 2000 (fig 03 and 04).This miraculous

order to move these areas into the

shiny effects, acquires a statute similar

Nostrae Laetitiae” in the Basilica of

Virgin and Child is still a popular subject

background …” . This is usually

to a pictorial layer.The retouching was

Tongres (15th c.) is still an important

of devotion in Liège. As in the previous

achieved by retouching these white

carried out by applying small dots of

object of devotion. The procession that

example, the salient parts showed

remains or spots to match the tone

a reddish colour close to each other

occur every 7 years is considered a great

many losses revealing the underlying

of the wood in order to restore the

in order to distinguish the retouching

event in Belgium.The sculpture was the

wood. The worshippers seem to have

structural continuity of the volume.

from the remains of bolus.

object of a restoration treatment in

made it a practice to strip off the

the early 1990s. Fillings were applied

gilding and take the fragments with

to the top of the outstanding folds.

them, possibly because they ascribed


In the case of theVirgin from La Gleize (13th century - Museum Grand Curtius,


1. 4 Retouching on fillings


When it appears necessary to fill a lacuna for conservative or aesthetic

Liège), losses with exposed bare wood

Even though in general we advise

Conservators chose to mimic the

magic properties to them, as being

are integrated as explained before and

to leave lacunae that reveal the bare

worn areas revealing the bolus, which

relics. For reasons of conservation, but

thus left visible, whereas in the more

wood visible, in practice certain losses

was applied with large brushstrokes.

also in the hope of putting a stop to

extensive lacunae revealing the white

may be judged to be disturbing, for

This intervention it is well-documented

this practice, it was decided to fill in

preparation, the retouching mimics the

example because of their geometric

with photographs and easily reversible.

these lacunae. A pointillist retouching

gilding by applying overlapping glazes.

shape. Other losses can interrupt

It is nevertheless difficult to distinguish

with pure colours was carried out on

To ensure reversibility of the inpainting,

the fluidity of a drapery or even

the original gilding from the retouching.

the fillings and on the zones revealing

the choice of retouching materials and

be interpreted as an iconographic

This is due to the perfect mimetic result

the white preparation in the worn

solvents has to take the nature of the

element that is foreign to the work

of the intervention. This phenomenon

parts of the gilding. In the areas where

gilding (water or oil-based) and its

of art. The reasons for applying fillings

has been underlined by the Italian

the gold was still in good condition, the

sensitivity into consideration.

to gaps could be exclusively based

architect Camillo Boito in “Conserving

retouching was carried out in the same

Nome artigo

The materials used for retouching differ from the sculpture’s original materials to assure reversibility. The degree of gloss is determined by the binder and its concentration. The vibrant effect of this type of retouching compensates the absence of the metallic reflections of the gold leaf. In our opinion, in most cases, the addition of mica highlights is not necessary. We avoid it as much as possible. The pointillist technique is part of the large family of ‘stylised repetitive retouching’ alongside with the tratteggio or the “selezione effetto oro“, or the “interpolation“ or “camouflage“ used in Denmark since 1990 [9]. When applied to 3D objects, the advantage of the pointillist retouching seems to be that it doesn’t enter into competition with the form, which is sometimes the case with retouching with parallel hatching. This is due to the fact that the dots form a neutral motif as they are not arranged in a certain direction such as a line (no top or bottom, nor sides). Indeed, on

del originale” [10]. Interpreting the relief (3D) through the retouching (2D) introduces an element of tension and ambiguity. While the original gilding characterized the material of the relief (for example a drapery fold), the retouching is laid over the form as if it rebuilt it. This leads to a distortion that provokes a conflict in the perception of the relations between retouching and form on the one hand, and retouching and gilding on the other. It goes without saying that, with every type of visible reintegration, the final effect largely depends on the skills of the restorer. Some retouching have the tendency to visually step forward, accentuating the lacunae at the expense of the original gilding, which moves back. This phenomenon happens even in the case of the famous retouching of the Santo Vescovo, 14th c. in the Bargello museum in Florence, which can be considered as a milestone for the history of restoration. Indeed,

“The golden stain of time”: the inpainting of gildings on wooden sculpture


for the treatment of gaps seems to attest to the changing nature of our relation with time and space

. In


some countries, regilding seems to be acceptable for historic interiors whereas gilded surfaces on sculpture are treated as a pictorial layer. In other countries, regilding of sculpture is still a common practice. Following the concept of a ‘relative Fig 03 and 04 • Our Lady of St. Séverin (ca.1520) in St. Martin Church (Liège) after treatment.

Philippot, our point of view is that to be appreciated, a gilding on a wooden

this sculpture has acquired a historical

micas to reproduce the glittering

losses that showed the bare wood

sculpture doesn’t necessarily have to

value. We can also cite retouching

metallic surface in different colours.

and fragments of white and orange

be complete. This choice to preserve

grounds. In this case, after filling,

our understanding of the “golden stain

on the Christ by Cimabue, which has acquired a double value: a historical

1. 4 Decorative patterns with/on gold

we only carried out a pointillist

of time” [12] shouldn’t be interpreted by

one for the development of the

What happens when gilding is part

retouching in the gold colour of the

the broad public as the conservator’s

background without reconstructing

lack of knowledge or lack of skills

‘astrazione chromatica’ by Ornella


Fig 05 and 06 • V  irgin (ca.1440), in the church of St-Nicolas (Drogenbos), after treatment.

gap’ in sculpture formulated by Paul

of decorative patterns?

REFERENCES [1] TRIPP, G. “L’apport de Paul Philippot à la

de l’humidité relative sur le caractère

théorie et à la pratique de la restauration”. In

hygroscopique, la dureté et la réversibilité des

Pénétrer l’art Restaurer l’oeuvre, Groeninghe

comblements, Mémoire Master 2, Université

EDS (edité par C. Périer-D’Ieteren),1990,

Paris 1 Panthéon-Sorbonne, 2012-2013. [7] BERGEON-LANGLE, S. «De l’usure au

p.374. [2] STEYAERT, D. “The conservation of

manque, du comblement à la réintégration».

polychromy on medieval sculptures in Belgium







in the nineteenth century and its perception

conservation-restauration, Aproa-Brk, Vioe,

by de Royal Monuments Commssion of the

2007, p.10.

time”. In Conservation In The Nineteenth

[8] BOITO, C. “Il nuovo e l’antico in

Century, Archetype Ltd in association with

architettura”, Milano, Jaca Book, 1989, p. 107-

the National Museum of Denmark and CATS,


Casazza and Umberto Baldini, and a

During two conservation campaigns

the motifs. This solution enabled

in reproducing the original gilding

commemorative value referring to the

of the altarpiece of Our Lady, known

to avoid the use of a hypothesis to

technique. The message to be given

[3] SERCK-DEWAIDE, M. “Conservation

In Reflexions on the aesthetic completion of

incident that profoundly marked the

as the Saluces altarpiece, in 1973 and

replace the missing patterns of the

out is that it is a choice that consists in

et restauration au palais royal de Bruxelles

wall paintings, CeROArt [en ligne], HS/juin

city of Florence: the flood of 1966.

1988, it was decided beforehand to

polychromy and at the same time,

integrating the loss as a witness of the

et au château de Laeken”. In Dynastie et

2015, mis en ligne le 19 mai 2015, consulté le

In some cases, however, the pointillist

not carry out a chromatic reintegration

it has allowed us to reconstruct the

material history of the object.

Photographie, 2005, p.71-82.

26 septembre 2017. URL: htt://ceroart.revues.

technique does not appear as the

but to leave the wood exposed in

continuity of the volume and of the

In practice, there are no default

optimal solution. This case can be

the losses even in the parts that are

material: gold. All in all, it is as if we

decisions.That is why it is so important

illustrated by the frame of the

decorated with rich applied brocades.

had artificially moved the deep gap to

to make a concerted decision according

altarpiece of St. Denis. The lacuna had

A different approach was chosen

an upper level that is estimated more

to each case. Whenever retouching is

a geometrical shape and was situated

for the treatment, in 2003, of the

acceptable or at least less disturbing.

needed, the use of pigments in various

in the middle of the frame. In this case

Virgin (ca. 1440) in the church of St.

small mica (minerals from different

Nicolas, in Drogenbos, which raised

silicates) highlights were added to

the question of the reconstruction

restore the metallic effect and to

(recognizable or not) of the motifs

Depending on the nature and on

the optical continuity of the gilded

better harmonize the retouching.

in the losses. The protruding parts

the function of the gilded sculptures

volume, ensuring the distinctness and

Finetec® provides a wide range of

of the garment folds again had deep

or ensembles, the variety of solutions

reversibility of the intervention.

Nome artigo

mediums makes it possible to carry out CONCLUSION

a harmonization of the surface colour and allows to perfectly reconstruct

[9] BRAJER, I.“To retouch or not to retouch?”.

2013, p. 97.

[4] Gamme patrimoine de chez DAUVET (feuilles d’or, d’argent et d’alliages, format 80

org/4619, p. 16 [10] CASAZZA, O. “Il Restauro Pittorico nell’Unità di Metodologia”, Nardini (Ed.), 1981,

ou 84 mm de côté). [5] SERCK-DEWAIDE, M. “Réflexions à

p. 16

propos des dorures du salon des Palmiers

[11] PIPLANI, N. “Theoretical underpinnings

de l’Hôtel Hayme de Bomal à Liège (1775-

of conservation in India”. In Conversaciones

1780)”. In Dorure et polychromie, Bulletin 4

con Paul Philippot, Revista de conservación,

de l’Aproa, 2013, p.12-18.

Instiuto Nacional de Antropologia e Historia



P. “La


(México), 2015, p.83.

des lacunes du support bois”. In Etudes

[12] RUSKIN, J. “The seven Lamps of

comparatives sur les matériaux de bouchage

Architecture”, In The Lamp of Memory, 1859,

et les techniques de réalisation. Influence

Aphorism 31.

“The golden stain of time”: the inpainting of gildings on wooden sculpture


Keywords Polychrome wood; Faux marble; Total inpainting;


Gilding; because it was cheap, but also because

Glazed silver.

it was an available and light material. Today, the altar architecture and its elements are overpainted and the paintings are lost. The entire altar was dismantled in 2001 due


to the restoration works on church The imitation of marble, as one of the techniques of illusionism, has been frequently used from east to west, in churches and in palaces, from the early Roman period to the present day.The imitation has been used on different

Maja S. Miklin

types of substrates and supports – from fresco paintings on walls, plaster

Department of Conservation and Restoration of works of art, Academy of Fine Arts, Zamenhoffova 14, 10000 Zagreb; maja.sucevicmiklin@gmail.com

columns (scagliola) altars



and wooden

to sheets of paper (ebru).

Therefore, every support had to be prepared with the appropriate use of pigments and binders. It was not always easy to imitate a


more or less genuine material, but it

and it is now stored after a detailed

was much cheaper and the function of

examination, analysis and restoration

the imitation was simply decorative [3].

probes, with all of these processes

Due to the width of the topic

thoroughly documented.

marble imitations this presentation

So far, only the tabernacle has gone

will focus on the painted faux marble

through a complete restoration process,

on Croatian wooden altars from the

which included the joinery repair,

baroque period. The reconstruction

overpaint removal, reconstruction of

of the faux marble paint layer will

the wooden support, consolidation,

be presented on an example of

reconstruction of the ground, gilding,

restoration of the wooden tabernacle

paint layers and varnishing.

located in the church of Saint Benedict in Gornji Kraljevec, Hrašćina

1.2. The technological layers and the


state of the original

The examination of the original layer 1.1. The baroque wooden tabernacle

is needed for reconstruction of every

The wooden tabernacle was added in

paint layer. A choice of the painting

the inpainting was done in gouache, a

the second quarter of the 18th century.

technique or a way in which the paint

This paper will present the faux marble techniques that use paint on polished ground.

reversible technique that can be both

It is oversized and mounted in front

layers or brush strokes were applied

The focus will be on the conservation-restoration of the baroque polychrome and

transparent and opaque. The brush

gilded wooden tabernacle located in the church of Saint Benedict in Gornji Kraljevec,

of the altar painting. It is a part of the

depends both on the purpose and

strokes methods such as tratteggio or

Hrašćina (Croatia). The tabernacle is a place where sacraments are preserved for the

puntegiaro were not used because they

17th century wooden altar and one of

location of the object and on the

sacred communion.

would emphasize the already existing

the rare examples in northern Croatia

technological layers and the state of

The reconstruction of the tabernacle’s marble imitation (i.e. inpainting tests, the

visual vibrancy of the marble pattern.

where the entire iconographic program

the original.

choice regarding the appropriate painting technique, and the process of applying


the paint to imitate the artist’s brush strokes and match them with the state of the

executed using brushes of different sizes

statues.The wood was widely used as a

it was discovered underneath a

original paint layer) will give an insight into both the inpainting method and the

and imitating the original paint layer.

support for marble imitations not only

paint layer imitating marble. The

Illusionistic painting has been frequently used throughout history and in various art

process of painted faux marble.

periods. It was executed in the interiors of both secular palaces and religious places.

After preliminary and practical research,

One of the most popular illusion themes was the imitation of stone, especially marble.





is presented with paintings, and not with





Figure 2 • Different tools and strokes

original paint layer was executed in

pink, purple and blue. The paint was

marble type either in color patterns or

only mean that the faux marble was

The veins are executed in irregular

tempera on a polished white ground.

applied in a free style – patterns of

in the application of the paint.

made according to some template

motion and darker tones of blue and

Tempera is a very solid and durable

simple stains placed uniformly and

and that it was mainly decorative.

purple. The veins are thin, short and


with accented veins.




One of the most widely used imitations was semiprecious stone

round or pointy at the end. If they had been done with a small pointed

environmental fluctuations resulted in

The four basic types of marble

lapis lazuli that was often executed

1.3.1. Tools and paint application

wood movements that affected not

(veined, brèche (breccia), cloudy and

with paint on a polished ground

In order to choose the right method

The second layer are stains that

brush, the brush would have created

just the paint layer, but also the ground

onyx or agate) and the presence of

or with a glaze on sliver leaves

and the technique for reconstruction

create the pattern in pink, purple and

longer strokes because the brush can

and the gilding which in turn resulted

veins could suggest that it is a veined

decorated with gilded veins

. The

of the paint layer, we first have to

blue tones. The pattern was built up

hold quite an amount of paint. Short

in cracks and large losses. Also, poor


. However, the way the stains

gilded veins actually represented the

understand the way the original paint

in a more or less opaque paint, letting

strokes done with a wing feather

church maintenance did not help the

are applied, it resembles more a

sparkling pyrite, also known as “fools

was applied and the materials that

the lower layers dry completely

also did not produce veins similar

preservation of the tabernacle.

cloudy type of marble.

gold”, the mineral that is commonly

were used in its application.

before the new layer was built up.

to the original ones. However, using


Although the imitations of marble






applied polished white preparation.

. The

To create patterns and streaked

By looking closely, we can see that

the feather again and holding it like


1.3. The paint layer – imitation of

were sometimes done realistically

technological layers for this kind of

effects, artists used different tools:

the stains were applied so that the

a quill created thin and short strokes


(marbling) to the point that one could

marble imitation demanded different

paintbrushes of various forms made

edge is both smooth and uneven.This

identical to the original ones.

The original palette colors that

recognize a marble type, it is not

kind of procedure – applying ground,

from mammals (hog, badger, sable,

pattern was similar to that executed

The partially applied dots were

were used are light pastel tones of

uncommon to be unable to define the

yellow and red bole then silver leaves

squirrel), bird feathers (like goose or

with a big mop brush, especially if

done by splashing the opaque paint

on which the blue glaze was painted.

peacock), pieces of cloth or leather,

“broken-in”, but the shape made with

with a coarser brush.

If not protected the silver would

brushes and natural sponges, i.e. the

this brush was too circular. So, none

During the overpaint removal, the

oxidize or, if damaged, the red bole

materials that are all still familiar to

of the brushes could have been used.

surface was left covered with an

would be visible [7].

modern-day artists

. However, the

The other tool that could have

uneven patina to avoid the over-


development of the industry and

been used in the 18th century is

marbles (marbelizing) could have

art painting techniques (like acrylic

natural sponge. The sponge gave

been inspired by forms and colors

paint) has yielded tools that are more

better effects and created the stain

of individual decorative stones and

advanced in materials (like synthetic

that was not circular in shape, and its

minerals, but they did not have to

fibers), shapes and sizes and that

edges were all identical.

imitate the specific marble because,

can create almost the same effect as

The other tool that was, and still is,

basically, the main tendency of the

traditional ones and can be therefore

used for marbling, is a bird feather.

altar polychromy was to decorate

used instead of them.

While wing feathers can give streaked

The brush strokes were always so

Figure 1 • The tabernacle before inpainting and gilding



The first layer is actually uniformly

Maja Sučević Miklin



cleaning of the paint layer. 2. MATERIALS AND METHODS Marble imitations have been always painted freely on big surfaces with wide, fluid strokes.

and not to present a specific material.

For the purpose of identifying the

effects only, tail feathers have a more

visible because marbling was always

A geological examination and art

original strokes on the tabernacle, a brief

rounded tip and by holding them in

viewed from a distance and the

historical analysis lead to the conclusion

catalogue of strokes was made using

hand like a pen, they could give better

emphasis was not placed on details,

that the imitation of marble on the

the tools that are known to be used

results and produce stains identical to

but on the effects and the unity of the

tabernacle was not realistic enough

for marbling. For easier identification of

the original ones.

bigger picture [9]. The best way to see

and since it cannot be traced to its

the tools, the painted faux marble must

altar to put it into a context, it could

be divided into layers.

The third layer are veins with partially applied little brown dots.

this it to take a part of marbling out of its context.

A case study on reconstruction of the faux marble paint layer on a baroque wooden tabernacle


Sometimes the paint was applied wet-on-wet, which required work to

achieved not after splashing with

the wanted restoration precision.

traditional, but with modern tools like

be done fast. Sometimes, however, the

The surface of the new ground was

toothbrushes. It created dots of the

paint was built up in layers letting the

polished, adjusted to the original by

same shape, ranging from very small

previous layer to dry. Whatever the

imitating the cracks with a fine, thin

to medium sized dots.

method of painting, it is easier to paint

needle, and isolated.

a less diluted paint, this created dots

applying local, transparent tone with

identical to the original ones and by

After the inpainting tests, the

medium flat paintbrush that covered

diluting the paint with more water,

traditional methods of reconstruction,

the whiteness and the whole surface

we obtained the effect of patina.

like tratteggio with vertical lines or

of the new ground.

The surrounding original paint was

something that is already there. Figure 3 • Prepared ground



When the dots were applied with by

something new than to reconstruct

Figure 4 • Reconstruction of the forms of the marble pattern

different sizes were used to obtain


puntegiaro, have created vibrancy of

The forms of the marble patterns

retouch and illegibility of the marble

were marked using a small round-

pattern. Only the total inpainting

pointed synthetic paintbrush. The

reconstructions were protected with

enabled the new reconstructions to

tones were gradually applied, letting

varnish based on natural resin.

fit better in the surrounding area and

each layer and surface to dry. By

The gold and silver were applied,

not to disturb the already sufficient

doing so, the layers could be built up

burnished, adjusted to the original with

playfulness of the image.

without removing the latter one.

gouache and iron wool and protected

Making the list of different brush

successfully integrated and the unity




Figure 6 • The tabernacle after conservation-restoration treatment

with varnish. The reconstruction of

strokes and finding out how the original

of the visual impression was achieved.

gouache, the best painting technique

care of every detail and characteristic

the glaze was done with gouache

paint was applied confirmed the usage

During the 19th century, the baroque

that could imitate tempera because

of each marble pattern, and even

colors, varnished and completed with

of traditional tools that were the most

flamboyance of painted surfaces and

of its good coverage quality, matt

more of the balance between the new

resin-based colors.

accessible in the 18th century.

ornaments on altars was considered

effect, water solubility and reversibility.

reconstruction with the surrounding

When it comes to retouching, it




the tabernacle.

layer – total inpainting


reconstructions of different sizes, and

Maja Sučević Miklin


In this process, it was crucial to take

2.1. Reconstruction of the paint



The inpainting tests were done with

original and the whole appearance of

Figure 5 • After reconstruction

protected with a sheet of paper.

The substitution of traditional with

tasteless and it was undervalued. To

more modern tools created the same

avoid that colorfulness, polychromy

affect and, what is most important, the

was often overpainted monochrome.

restoration precision was achieved.

The overpainting was the only link

The color for veins was opaque,

In the case of Hrašćina’s tabernacle,

applied with a small round paintbrush,

the total inpainting was the best choice

From the restoration aspect, the use

between the added 18th century

imitating the characteristic motions

because it is mounted on top of the

of gouache colors was appropriate.

tabernacle and the 17th century altar.

and shortness.

mensa at the eye level of the observer

It was also appropriate from the

After restoration of the wooden

and other methods of retouching would

technical point of view – transparent

tabernacle, the original painted faux

have been vibrant and more visible.

colors were good for applying

marble layer was presented. This

it is limited to imitation of the given

The little dots were not made by

template. By applying paint freely,

using a paintbrush because they did

the movement of the original stroke

not leave the right circle form and

The full understanding of the way

and gradually building up layers,

opened a way to new research, but

was achieved. Additionally, since the

were all of the same size. If we look

the original paint was applied made

and opaque colors were good for

also a discussion on where and how

feather cannot be controlled on

at the list of different strokes, we

the reconstruction of the paint layers

imitating veins.

the tabernacle will be presented in

small reconstructions, the brushes of

can see that the best results were

easier and alike.

The new reconstructed parts were

the future because the altar’s marble

A case study on reconstruction of the faux marble paint layer on a baroque wooden tabernacle


imitation is very different and it can not be seen as a whole. 4. CONCLUSIONS Knowing the colors and patterns of painted marble imitations is very important because it can determine types of altars, their change through periods of time as well as attributions. It is important not only for the purposes of the history of art, but it also has some practical implications – knowing how marbling effects were done can be helpful when it is time for restoration.

REFERENCES [1] ZAJEC, Vlasta – Štukomramorni oltari u Sjevernoj Hrvatskoj. Radovi Instituta za povijest umjetnost. Vol. 35, (2011), pp.177-194

pp. 74-75 [5] ARANICKI, Andrej; JEMBRIH, Zvjezdana

[7] ARANICKI, Andrej provedenim




radovima, oltar Žalosne Majke Božje, kapela sv. Ladislava, Podgorje Bistričko, 2014.

[2] TAUBERT, Johannes – Polychrome Sculpture:

– Konzervatorsko-restauratorski radovi na

Meaning, Form, Conservation. Los Angeles, CA:

bočnom oltaru sv. Josipa iz župne crkve

[8] DORGE, Valerie; HOWLETT, F. Carey –

Getty Conservation Institute, 2015, pp. 108-119

Presvetog Trojstva u Legradu – Godišnjak

Painted wood: History and Conservation, The

[3] DORGE, Valerie; HOWLETT, F. Carey

zaštite spomenika kulture Hrvatske 31/32-

Ghetty Conservation Institute, 1998, 114 page

– Painted wood: History and conservation. Los Angeles, CA: Getty Conservation Institute, 1998, pp. 110-117 [4] FINKELSTEIN, Pierre – The art of faux,


Watson-Guptill publications/New York, 1997.,

Maja Sučević Miklin

2007/2008, Ministarstvo kulture, pp. 215-236. [6] ŠKARIĆ, Ksenija – Polikromija i polikromatori oltara 17. i 18. stoljeća u Sjeverozapadnoj Hrvatskoj,

[9] BARIČEVIĆ, Doris – Barokno kiparstvo Sjeverne Hrvatske. Zagreb: Institut za povijest umjetnosti, Školska knjiga, 2008, pp. 387, 390

Doktorski rad, Zagreb, 2014, pp. 80-167

Nome artigo




retouching approaches on paper with

With gelatin it takes more than 1

the selection of a retouching method

houre for water apsorption time.

Different types of Japanese paper

optimal for achieving even color

Tosa Shoji (40 g/m2) - 50% kozu

are used as surface for retouching

distribution and avoiding potential

fibers and 50% pulp, high absorption.

of art on paper and some are high


We reduce the apsorption time from 30 secunds to 5.30 minutes with

absorption because they contain very little or no binder at all. As

1.1. The absorption test on

the paper is highly absorbent, it is

non-insulated and insulated

necessary to reduce the absorption

Japanese paper surfaces

4% starch glue. Usumino Shiro (17 g/m2) - 100% kozu fibers.

of its fibers. As it is already mentioned

Different Japanese paper surfaces

this work deals with absorption and

Takogami, Tosa-Shoji, Usumino-Shiro,

In its structure contains emulsion which reduces the absorption.

Table 1 • Water absorption time on non-insulated and insulated Japanese paper surfaces WATER ABSORPTION TIME








Tosa Shoji


Methyl cellulose

Starch glue











33 s

1 min

2.45 min

43 s

1.36 min

50 s

10.42 min

15 s

30 s


30 s

47 s

3.45 min

2.13 min

5.30 min

1.25 min

1h i 20 min

10 s

2 min

Usumino Shiro


5.30 min

10.30 min

19 min

14 min

38 min

1.23 min

2h i 33 min

6.35 min

11 min



7.47 min

2h i 08 min

3h i 03 min

54 min

2h i 09 min

2h i 25 min

3h i 14 min

1h i 17 min

2h i 05 min



10.25 min

1h i 17 min

3h i 18 min

30 min

1h i 57 min

2h i 34 min

3h i 23 min

1h i 30 min

1h i 54 min

Croatian State Archives, Central Laboratory for Conservation and Restoration, shuzjak@arhiv.hr

Gampi i Mistumata with no insulation

Gampi (12 g/m2) and Mistumata (11 g/

and insulated with adhesives in 2% m2) - because of its fiber characteristics and 4% - methyl cellulose, starch glue, have great resistance on absorption


wich takes more than 3 houres.

gelatin and klucel. RESULTS:

Retouching on paper requires a unique approach and attention due to paper’s capacity

how to cover and retouch the brown

of absorption, paint spills, and change of color tones caused by the absorption of fibers


(Chapter 1.3. I., Figure 1). This work presents different approaches to retouching artwork


on paper in the Laboratory for Conservation and Restoration at the Croatian State Archives.

The following example, a map of Zadar

It also presents how to reduce the absorption of fibers and prepare perfect paper surface

(Chapter 2.1. II.), deals with the approach

for retouching on two examples (Chapter 2), a Watercolour Landscape and a Map of

to retouching to equalize the tones of the

Zadar from 19. Century. A Watercolour Landscape example (Chapter 2.1. I.) explores

aesthetic and visual whole.








Takogami (43g/m2) - contains 100% 1.2. Color on insulated Japanese kozu fibers, high absorption. Absorption



paper surfaces with adhesives

How does the color behave on high

surface is 33 secunds and with 4% absorbent Japanese paper insulated with methyl cellulose we slow down the different adhesives in 2% and 4% - methyl apsorption on almost 3 minutes. cellulose, starch glue, gelatin and klucel.

color tone more than other adhesives and leaves the paint brush-strokes.

Figure 1 • Japanese paper insulated with different adhesives in 2% and 4%- methyl cellulose, starch glue, gelatin and klucel

RESULTS: Methyl cellulose 2% - changes the color tone. Methyl cellulose 4% - gives good results. Starch glue - gives good results but it must be perfectly prepaired to avoid color spots and stains. Gelatin 2% - gives good results. Gelatin 4% - gives good results but for retouching purpose is too strong. Klucel – contains ethyl alcohol that reduces a surface tension. It changes the

Figure 1


Sanela Huzjak

The paper retains color as a separate layer, not absorbing into the fiber


I. Non-insulated Japanese paper

structure. This allows for even and clean application of color without

surface II. Insulated Japanese paper surface,

spillage or staining. Color can be

III. Color mixed with adhesive on

applied in several layers. Paper surface

Japanese paper surface

insulated with an adhesive should be

Deep red watercolor on high absorbent Japanese paper I. Color on non-insulated Japanese paper surface Color is not retained as a separate layer but is absorbed into the fiber structure of the paper. Color spillage and stains occur, especially when laying the base tone. It does not allow nice color application. II. Color on Japanese paper surface

Figure II

Figure 1 • Watercolour Landscape before retouching

insulated with 4% methyl cellulose

with several layers is more difficult. Color containing a high percentage of binders can crack when applied thickly. 2. MATERIALS AND METHODS

left for at least 24 hours to completely

2.1. Presenting various approaches

dry and to form an insulating layer/film.

to retouching on the examples of

III. Color mixed with adhesive 2%

artwork - Watercolour Landscape

methyl cellulose on Japanese paper

and a Map of Zadar from the 19th



Color is retained as a separate layer and its absorption into the paper surface is reduced. Mixing gives fullness to the color, though it becomes more transparent when applied. It allows for smooth color application. Working

Figure III

Figure 2 • Watercolour Landscape after retouching

Figure 3 • Retouching as reintegration of the painted layer without impact on the structure of the artwork

II. A Map of Zadar from the 19th

I. Watercolour Landscape

Century, State Archives in Zadar Painted

Watercolour on paper is damaged



(Figure of


with distinct brown stains of unknown



origin. The brown stains cannot be

watercolors and black ink on a cotton

removed or reduced, but aside from

canvas attached to the paper support.

visually compromising the piece, they

The canvas was impregnated with

have no effect on the stability of the

starch adhesive as the painting surface.

paper support (Figure 1). Visually, the

The Map was in an extremely bad

piece was balanced using retouching

condition and it required complex

in the following way (Figure 3) - the

conservation and restoration work.

shapes of the brown stains were traced

During the process, the old paper

using a tracing paper. Next they were

support was removed from the back

covered with Japanese paper Tosa

of the map and replaced with a new

Shoji. Tosa Shoji was coated with 4%

one. After achieving the appropriate

methyl cellulose adhesive to reduce the

conditions, Japanese

absorption of its fibers. So prepared

selected for achieving a tone balance.

retouching surface is separated from

Selected were Usumino Shiro laminated

the original artwork paper support and

with Kizuki kozu Japanese papers

it is completely removable. Retouching

and colors for paper toning, Pergasol

was made with watercolors following

from Gabi Kleindorfer (Figure 2). The

the character and the form of drawing

selected and toned sample of the

(Figure 2 and 3).

Japanese paper had to achieve the


Figure 1 •  The Map of Zadar before conservation and restoration


Figure 2 •  Selected and toned sample of the Japanese papers

Retouching approaches to artwork on paper in the laboratory for conservation and restoration at the croatian state archives


Figure 3 • Reconstruction of the missing parts with toned sample of the Japanese paper and retouching with watercolors in tratteggio method

requirements such as thickness, texture



retain as a separate layer but absorbs

binders can crack. (Chapter 1.3. III.,

and tone of the color. Toned Japanese

paper (Figure 2 and 3). Watercolor

it in its fiber structure (Chapter 1.3. I.,

Figure 3). For paper surface insulation

paper was used for achieving a tone



Figure 1). To reduce that absorption

we use adhesives in 4%. It is important

balance of the visually aesthetic whole

drawing of the map were as few

of fibers we use insulation with an

to form an insulating layer/film so

but also as the additionally reinforced

as possible. Parts with missing the

adhesive directly on Japanese paper

it needs for at least 24 hours for

of canvas drawing support. The

original historical architectural data

surface (Chapter 1.3. II., Figure 2) or

adhesive to completely dry (Chapter

retouching was applied with using the

are visually connected with toned

addition of adhesive into the color

1.3 .II., Figure 2). Klucel is not for

tratteggio method, and no base tone

Japanese paper (Figure 3 and 4).

(Chapter 1.3. III., Figure 3). Adhesives

recommend because it contains ethyl

we use are methyl cellulose, starch glue

alcohol that reduces a surface tension.

and gelatin in 2% and 4%, (Chapter

It changes the color tone more than

1.2., Figure 1) depends of the artwork

other adhesives, leaves the paint brush-





was required. Some surfaces required no retouching at all (Figure 3 and 4).


Visual and aesthetic balance on

Absorption of some types of Japanese

and what method is necessary. For

strokes and it is not compatible with

the Map of Zadar was achieved

paper used as surface for retouching is

colors mixed with an adhesive we

every material (Chapter 1.2., Figure 1).

using a combination of watercolor

a problem because the color does not

use adhesives in 2% because color containing a high percentage of

Figure 4 • The Map of Zadar after conservation and restoration

4. CONCLUSIONS The paper surface for retouching requires




reduce the absorption of its fibers. By insulating the paper surface as the base of retouching or addition of adhesive into the color, we try to reduce its capacity of absorption.


The surface prepared in such a way

CHOI, S., MAKIN, J. – Treatment and Hausing

retains the retouching as a separate

Techniques for Pastel Paintings on Paper: Case

paint layer and allows even and clean

Studies, The Book and Paper Group Annual

application of color and working with fine details without spillage or staining (Chapter 1.3. II. and III.).

32, 2013. American Institute for Conservation (AIC) Book and Paper Group - 30. Inpainting and Design Compensation. Paper Conservation Catalog (PCC), 9th Edition, Copyright AIC/ BPG 1994. POULSSON, T. G. – Retouching of Art on Paper. London: Arhetype Publications Ltd, 2008.


Sanela Huzjak

Retouching approaches to artwork on paper in the laboratory for conservation and restoration at the croatian state archives


Keywords Colour reintegration; Stains;


Drawings; Figure 1 • Diverse stain and paper examples shown by different watercolour drawings. Microphotographs (x52) taken with DinoLite AD7013MZT(R4)

Acrylics; Lampshade; Embossed paper.

1. INTRODUCTION Chromatic reintegration of artworks on paper has always a potential for problems to occur, specially if one encounters different types of paper mixed with different medium materials and conservation problems. At




Laboratory several objects shown these situations, and so divided into

Leonor Loureiro

groups: a) Delfim Maya’s watercolour

Instituto Politécnico de Tomar, Quinta do Contador, Estrada da Serra, 2300-313 Tomar; leonorloureiro@ipt.pt; leonorloureiro@gmail.com

disrupting stains, in different papers

drawings, displaying different types of

with the impossibility of performing chemical treatments specifically due to the owner requirements; b) graphite and




lacunae caused either by materials deterioration or by Lepisma saccarina insect attack (Figure 2); c) a Delfim Maya’s lampshade made of embossed paper, hand painted with black carbon ink, exhibiting heavy glue staining caused by a previous “restoration” attempt by the family.

(Figure 1) and mixed materials [1], and

Abstract The Instituto Politécnico de Tomar (IPT) continuously receives diverse paper

watercolours wash to cover disrupting stains that prevented objects overall

Apart of the implications regarding the

objects for conservation and restoration treatments. Decision making procedures are

observation; to test mixing reactions of different chromatic reintegration

direct application of chromatic materials

dependent on type and materials mixtures, objects formats, damages interactions,

materials; and to apply watercolours wash to different papers surfaces: plain

on paper objects, the results show that

or even by owners’ opinions.

and embossed.

a good chromatic reintegration result on

Tree situations posed complicated decision-making procedures: a collection of

The materials involved were Schmincke Horadam half pan watercolours,

the final work depends on the type of

watercolour drawings by the Portuguese sculptor Delfim Maya (1886–1978);

Windsor & Newton Artists half pan watercolours, Liquitex Acrylic “Heavy Body”,

paper, its surface finish, if it’s a full or a

graphite and charcoal drawings belonging to different private collectors; and a hand

Winsor & Newton Finity Acrylics, Derwent Charcoal pencils, and 3B Derwent

surface lacunae chromatic reintegration,

painted lampshade by Delfim Maya. All Delfim Maya’s objects dated from the 20th

Graphic Graphite pencil.

the mixes and the quality of the chromatic

century, and the charcoal drawing from 1899.

Different procedures for treating and/or disguising diverse types of stains

reintegration materials, and ultimately of

The interventions purpose was to assess methods on chromatic reintegration:

and discolouration were considered and questioned, and tricky techniques as

an experienced conservator’s hand working

its application on large and small areas of paper; to evaluate the application of

several layers of very diluted watercolour wash were applied.

on watercolour chromatic reintegration.

The interventions purposes were:

paper surfaces, as this would prevent

a) to assess several approaches on

the watercolours to partly penetrate

paper chromatic reintegration; b) its

the paper damaged fibres strata, thus

application on large and small areas of

reducing the coverage power and the

paper; c) to evaluate the application

required transparency.

of watercolours and acrylics wash on disrupting stains that prevented the

2.2 Graphite and charcoal drawings

overall observation of the objects; d) to test mixing different materials on paper chromatic reintegration; e) to apply watercolour wash to different papers

These objects needed different Figure 3 • “Untitled (woman)” 30’s caricatural drawing from Delfim Maya, before and after chromatic reintegration.

surface finishes: plain and embossed. Horadam half pan watercolours was 2. MATERIALS AND METHODS



[3, 4, 5]

For all the drawings, a mimetic Depending


787 [7]. Examples are clearly showed in Figures 3, 4 and 5. For some staining situations acrylics were also thought to be a good

methodology consisted in applying

included dismantling, dry cleaning

good coverage power, less material

directly a first wash coat of the opaque



applied, and a less time-consuming

and semi-staining Titanium Opaque

cleaning (cotton swab, wet blotters,

White 101, to cover and give a better

procedure. Liquitex1 Acrylic “Heavy

immersion), resizing, drying/flattening,

working base for the dark stained

tears consolidation, lacunae infilling,

areas.This was done either with 3/0 or


10/0 brushes, to control the coverage




precisely onto the stain shape.

Depending on the object constituents

After, a wash of other colours was

the chromatic reintegration materials

applied exactly inside the covered stain,

chosen can be slightly different. So,

and in conformity with the surrounding

for the three work of art groups in

areas, so to neutralize a “purplish” effect

discussion diverse approaches and

created by the Titanium Opaque White

solutions were applied.

101 wash, and applied in different situations, so to match the original colour

2.1 Delfim Maya’s watercolour

whenever possible: a) semi-transparent


and semi-staining Raw Umber 667; b)

Primarily, drawings,

Leonor Loureiro

and semi-staining Payne’s Grey Bluish

conservation treatments generally



Yellow Reddish 230; c) semi-opaque

result was the primary goal [6], so the

partout/frame mounting.

Figure 2 •  “Portrait of João Baptista de Sousa 1899” charcoal drawing, recto, and verso before treatment.

chromatic reintegration materials: a)




for the

the brand

Figure 4 • Face detail of “Dr. José Duffner” 30’s caricatural drawing from Delfim Maya, before and after chromatic reintegration.


opaque and semi-staining Naples Yellow


229, Jaune Brilliant Dark 221, and Naples

application hypothesis, due to their

Body” Unbleached Titanium 434 was chosen due to its colour, satin finish, possibility of dilution, known pigment composition (PW 6, PY 42, PR 101, PBIk 11), chroma saturation, availability, and known Material Safety Data Sheet


[8, 9]

In either case it was needed to apply a very thin coat of chromatic reintegration material and leave it to dry completely before applying the next layer. If this was not performed correctly, the colours might be mixed altogether, and the final effect ruined. No protective layer was applied previously to any of the stains at the

in “Sevilhana” and “Cavaleiro Cañero” graphite & iron gall ink drawings, the lacunae were reintegrated with a mixture of Schmincke Horadam half pan semi-opaque and semi staining watercolours of Ivory black 780 with Sepia Brown 663, and later traces of 3B Derwent Graphic Graphite pencil were used; b) in “Portrait of João Baptista de Sousa 1899” charcoal drawing were used Derwent Charcoal pencils in dark, medium, and light shades, and Schmincke Horadam half pan semi-transparent and semistaining watercolour Raw Umber 667. The “Sevilhana” and “Cavaleiro Cañero” lacunae infilled




primarily Japanese

paper and 4% Tylose MH 300 glue, thus did not needed a protective coating application. The chromatic reintegration was done by mixing Ivory Black and Sepia watercolours, and applying a mimetic layer on top of the lacunae. After flat drying, a finish touch of 3B Derwent Graphic

Figure 5 •  Body detail of “Dr. José Duffner” 30’s caricatural drawing from Delfim Maya, before and after chromatic reintegration.

Aproaches to the conservation treatment and chromatic reintegration on watercolours, charcoal drawings, and a lampshade handpainting


Figure 7 • Top left corner detail of “Portrait of João Baptista de Sousa 1899” charcoal drawing, during chromatic reintegration.

Graphite pencil was easy to apply (Figure 6). For the “Portrait of João Baptista de Sousa 1899” charcoal drawing, a thin coat of 4% Tylose MH 300 was firstly applied onto the paper surface lacunae as a barrier for the chromatic reintegration, and as a protective layer for the open and fragile insect bitten paper fibres. After




consisted in applying layers of dark, medium, or light Derwent Charcoal pencils by means of a point of a KohI-Noor Hardtmuth stump2. This tool was and still is used by artists to blend charcoal, pastel, or pencil drawings. It was naturally chosen as a tool Figure 6 • Head detail of “Sevilhana” 30’s drawing from Delfim Maya, before and after chromatic reintegration.

that specially allowed a much better control over the material application in

over blending pointillism effect, and led to an undertone effect. A masque of Archival buffered blue-grey box board 1 mm thick was also used to reduce “visual noise” created by adjacent white areas, as shown in Figure 7

Leonor Loureiro

enough to match or cover the paper colour. In these areas the application of a wash of Raw Umber 667 was needed. Two tests were performed on a corner: a) a first application of the by

the charcoal application; b) a first application of the charcoal, seconded by the watercolour wash application. It was concluded that a better effect and colour control was possible by the second test, therefore this was the chosen methodology. This work is still ongoing due to the high number and lacunae extension, and due to the necessary time needed for properly training the student, Ana Sofia Sousa.

the minute surface lacunae (between 1 to 0,1 mm diameter), with an all-


areas, the charcoal colour was not

wash, seconded

effects and maximize colour coverage,

After discussion, the first two options

scalpel removed, and after cleaning, the

Winsor & Newton Finity Acrylic (now

were discarded by the owner’s

lampshade still showed some staining

Professional Acrylic) Raw Umber 554

requests, and by the possible further

with tide lines surrounded by lighter

[10] was the second chosen material

damaging interactions of a chemical

paper areas. Overall, this was disruptive

and matching colour.

treatment to the stain adjacent areas

After testing, the methodology

or the undamaged overall work of art.

In this case the embossed paper and

chosen consisted in applying very

So, even though ethically controversial,

its colour required a different approach.

thin wash layers of both materials,

the least interventive operation and

Firstly, the chromatic reintegration

first acrylic and after watercolour, and

only possible solution was a top

materials were also chosen due to

leaving each layer to dry completely

colour application on stained areas.

their known pigments composition,

prior to next application, so to not

Nonetheless, as the stains were visibly


mixing them.

disruptive, but stable, and the objects

and needed to be disguised.

It was noted that in bigger lacunae


most of the glue concentration was

2.3 Delfim Maya lampshade

Dry and wet cleaning tests were performed with smoke sponge, eraser, scalpel, and wet cotton swab, which resulted in a lesser application of deionised water as initially expected due to paper surface sensitivity. Therefore,



stability, workability, possibility of mixing

The brushes used were also the

were going to be stored in a controlled

together, possible reversibility upon and

same as before, with the addition

environment, this contributed to ease

after application, and proven application

of type 2/0, due to the embossed

the decision-making process.

on previous restoration situations.

surface and stain condition.

application have their own tricks. If

Covering with a body colour was not an option due to the satin and

Watercolours and acrylics wash


the covered area it is still too moist, a non-workable stain appears, blending

embossed surface of the paper. Hence, Schmincke Horadam Watercolour

3.1 Delfim Maya watercolour

colours altogether. In this case the area

Raw Umber 667, was the first option


needs to be immediately dried with a

The owner of the Delfim Maya

cotton swab or a piece of blotter, to


watercolour drawings clearly specified

prevent staining the original work of

surface fragility in some areas, a thin

for a minimum intervention done to

art. After, colour needs to be removed

protective layer of 4% Tylose MH

the objects, preferably limited to dry

and the reintegration work restarted.

300 was tested in a small tear zone.

cleaning only, but with the specific

If too much body material is applied

The result was that the stains came

request for removal of the disruptive

(Figure 8), the final effect might be

around again, as well as the tide lines.


non-transparent and dull, depending

material and matching colour. As




This ruled out the use of a protective

The options for an intervention in

on: the cover material, the amount

layer. Was also a sign that water

these cases are scarce, depending also

of covered area and/or on the type

would be a possible problem during

on the type of stain: a) local or total

of paper used by the artist. If this

chromatic reintegration, preventing

chemical treatment and/or washing;

happens, it needs to be totally and

the maximum colour matching effect,

b) scalpel removal of the damaged

very carefully removed by means of

or even darken the large chromatic

area (paper included); c) aesthetical

a cotton swab slightly moistened in

reintegration areas.To minimize water

colour surface cover-up.

deionised water.

Aproaches to the conservation treatment and chromatic reintegration on watercolours, charcoal drawings, and a lampshade handpainting


Figure 8 • Detail of too much Titanium White watercolour body application. Microphotograph (x52) taken with Dino-Lite AD7013MZT(R4).

It was observed that in some stains and/or

papers, the


wash was readily absorbed, and in other cases it stayed on top of the applied area. Probable explanations

and quantity, or paper surface finish – absorbent or damaged. Testing in some cases shown that it was possible to remove the chromatic reintegration done, but some papers shown too much absorbency for this to happen. In these cases, the chromatic reintegration was considered irreversible. Therefore, if it is needed to be removed in the future, the “ultimate” solution is a total removal of the damaged area, and probably paper included. As it was not possible to pinpoint an exact cause for the absorbance or repellence due to the mix and diversity of situations encountered, it is recommended that careful though and

should firstly conduct tests and the work itself, prior to any attempt


Leonor Loureiro

application depends on the type

This was thick, brittle, embossed (as to

In any case there were not negative

of paper, materials and damages

look as cloth), and stained even after

mixing reactions of the different

encountered. It is the most time-

cleaning. Also, it could not be dismantled



consuming procedure and therefore

due to its construction method and

used. Large areas were considerably

also needs the helping hand of an

materials involved.

difficult to work with, comparing with

experienced conservator.


small or pointy lacunae. The ultimate

Further application and changes of

to perform this type of chromatic

took a long time to accomplish by

recommendation is that one should

the chosen chromatic materials will

reintegration by a non-trained person.

the student Laetitia Silva. During

always use the best quality materials

continue to be analysed, and this

After treatment all drawings were

chromatic reintegration two object

possible. Schmincke Horadam half

paper objects intervention will be

mounted in a passe-partout of



pan watercolours, Windsor & Newton

assessed in the future, as they will

Timecare Board ref. 600249. [11]

vertical and horizontal. The vertical

Artists half pan watercolours, Liquitex

remain within the Biblioteca Nacional

position of the paper shown that

Acrylic “Heavy Body”, Winsor &

de Portugal, Museu José Malhoa, and

the watercolour wash was difficult

Newton Finity Acrylics, and Derwent

accessible private collections.


to apply, as tended to downflow,

Charcoals and Graphic Graphite pencil

simpler and less questioned ones. The

not to be even, and the hand/brush

work very well altogether.

chromatic reintegration of “Sevilhana”

position created shadows over the

The application of watercolours

and “Cavaleiro Cañero” was applied

embossed paper. Placing the object

washes to cover disrupting stains that

onto paper lacunae areas, easy to be

in a horizontal position, preventing it

prevented objects overall observation

removed.Therefore, this action interferes

from rolling by means of small sand

lesser with the original. Regarding the

pillows, the chromatic reintegration

“Portrait of João Baptista de Sousa

action was visually eased, allowed a

1899” lacunae chromatic reintegration,

satisfactory general staining disguise,

some of the same problems as before,

more difficult to work with and

the application of a 4% Tylose MH 300

better control of the watercolour

with the adding situation of a more

tend to concentrate colour between

coat as a protective layer allowed an

or diluted acrylic flow, nonetheless

difficult removal of the watercolour

“valley” areas. Different paper surfaces

easier pointillism performance of the

maintaining a lighter undertone on

and acrylic colour mix applications.

imply careful problem analysis, to

The author wants to specially thank

reintegration charcoal. Nonetheless, in

large areas than the actual paper

better assess possible damages caused

the 2016-17 Paper Conservation

this case a final overall result is still in

colour. It was only difficulted by the

by colour and materials applications. It

and Restoration students for all the

to come, but the so far results show

conservator’s body working position,

is recommended that, if timeframes

work and dedication put in these

a good blending but with a disguisable

but this was surpassed by pausing



objects and studio/laboratory work.

bluish undertone.

more and do stretch exercises.

positive results. Stains were disguised

be taken to paper sizing, drawing

Without their help and overtime


materials and stains, to determine

given the conservation procedures in

their natures and possibly allow other

this paper would be very difficult to

treatment hypothesis to arise.

achieve in the necessary timeframe

3.2 Graphite and charcoal drawings






This intervention was meant to last

procedures should be taken previously. Also, that an experienced conservator

well, also with graphite and charcoal.

Therefore, the overall treatment

for this are the nature of the stains – repellent or not – and sizing quality

reintegration onto large areas of paper.

3.3 Delfim Maya lampshade

due to the stability of the applied

Figure 9 • Delfim Maya Lampshade, before and after treatment.

was considered successful even on different papers surfaces: plain or embossed. Embossed papers are

4. CONCLUSIONS Overall aims were met and with minimal



quantity application to the objects.

The lampshade was the trickiest object

materials. Either way, if it ever needs to

Mixing layers of watercolours and

to conserve and perform a chromatic

be restored again it will probably show

acrylics in chromatic interventions work







for the three 2017 exhibits.

Aproaches to the conservation treatment and chromatic reintegration on watercolours, charcoal drawings, and a lampshade handpainting


NOTES 1 Founded in 1955, Liquitex is one of the first brands to develop acrylic paints for artists: in 1956 developed “Soft Body” water-based acrylic paints, and in 1963 released the “Heavy Body” thicker consistency version. It is widely available. 2 This is called “esfuminho” in Portuguese, and “estompe” in French and German.

REFERENCES [4] LOUREIRO, Leonor – A Reintegração

gens para caracterização da obra gráfica de

Cromática de Cromolitografias. In RECH1: I

Delfim Maya. In ROQUE, Fátima Faria, ed. –

Encontro Internacional de Reintegração Cromá-


Delfim Maya. Escultor do Movimento. O Ribate-

tica de Bens Culturais. Porto. Comissão Orga-

November 2017].

jo na Obra de Delfim Maya. Vila Franca de Xira:

nizadora: Frederico Henriques / Ana Bailão /

Câmara Municipal de VFX, 2017, pp. 25-37.

Escola Profissional Árvore.

[8] LIQUITEX Official website. Available http://www.liquitex.com/AboutUs/ [26

[9] LIQUITEX MSDS Sheets - Heavy Body Artist Acrylic Safety Data Sheet. Available at:


[2] LOUREIRO, Leonor, et al. – Conserva-

[5] SILVA, Cátia; LOUREIRO, Leonor;

ção e restauro de desenhos e caricaturas de

ANTUNES Fernando – Inpainting a Urania


Delfim Maya: características e marcas de água

19th century toy theatre: problems and


encontradas nesses papéis do séc. XX. In Atas

solutions. In RECH2: 2nd International Meeting


do XII Congresso Internacional História do Pa-

on Retouching of Cultural Heritage Proceedings.

November 2017].

pel da Península Ibérica,Tomo II. Santa Maria da

Ana Bailão, Frederico Henriques, Ana Bidarra


Feira: AHHP – Asociación Hispánica de Histo-

(ed.), Porto: Escola Artística e Profissional Ár-

website – Professional Acrylic Colours.

riadores de Papel e Câmara Municipal Santa

vore, 2015, pp. 240-260.


Maria da Feira, 2017, pp. 433-455.

[6] SUSTIC, Sandra – Breve Manual sobre





Ana Catarina – Chromatic reintegration of

about Mimetic Retouching. Porto: Escola Artís-

November 2017]

20th century monochrome photographs

tica e Profissional Árvore, 2015. Official


[11] KOSEK, Joanna M. – Conservation website

Mountings for Prints and Drawings. A Manual

RECH3: Postprints. Ana Bailão, Frederico Hen-

HORADAM watercolour chart. Available

Based on Current Practice at the British

riques, Ana Bidarra (ed.). Porto: Escola Artís-


Museum. London: Archetype Publications,

tica e Profissional Árvore, 2016, pp. 113-122.

farbkar ten/colour_char t__HORADAM_

Leonor Loureiro



com/row/shop/acr ylic-colour/professional-

Reintegração Cromática / Brief Handbook




[3] LOUREIRO, Leonor; SILVA, Cátia; ROSA,

showing plain and textured paper surfaces. In


watercolours.pdf [26 November 2017].

[1] LOUREIRO, Leonor – Primeiras aborda-



Nome artigo


Keywords Photographic; Retouching; Technique;


Manipulation; called original. However, this practice


has usually, and still does, caused

Photographic procedures.

suspicion and is often a source of controversy. 1.1 State of the art


Both darkroom techniques and the In



the as

invention a



advancement was presented at the

Rubén Morales González Universidad Complutense de Madrid; Madrid, (Spain)ruben@rubenmorales.es;

Academy of Sciences in Paris; it was to radically change the way in which reality had been represented in two dimensions. Up until then, the responsibility of that representation fell solely on drawers and painters. Both science, which for centuries had studied and demonstrated that certain photosensitive salts could register light, and the socio-economic situation in the nineteenth century, eased the development of such an important invention.

Abstract Throughout the history of photography, many procedures have been used to attain

“original” in photography is quite hard

a final photographic image. Since the very beginning, photographic retouching was

to understand.

one of those interventions. Most of the preserved archives both in institutions and

Define terms and carry out an in-

private collections, contain negative and positive retouched photographs. However,

depth analysis of the photographic

the expression “photographic retouching”, suffers from an alarming lack of definition,

techniques are essential if we want to

even though it is an essential photographic procedure.

be able to differentiate them from the

Due to the negative-positive duality and the influence of retouching, the term

“true retouching”.

However, photography, presented in

retouching itself have intertwined

society through the daguerreotype,

for many years, which has cause

was born with two burdens: those who


thought that it was an unnecessary

misunderstanding, as we will see in this

vulgarity or even a disloyal rivalry,

paper.This has led to an unsupervised

and a series of technical and practical

and unorganized dissemination of

challenges that were standing in the

knowledge on the subject that has

way of obtaining a reliable image of

omitted one of the most important

reality on a sensitized plate which

secrets of photographic production:

rendered no color and which needed

photo retouching.





Nowadays, the change in era

long-exposure times. These and other scarcities that

regarding technological means has led

will be analysed later required an

to the popularization of photographic



capture and editing, a term designated

that consisted of several techniques

to include the set of tasks performed

and pictorial means to adapt the

after the shot. Edition is mostly carried

new invention to the inherited

out with a computer, or even on a

aesthetic canon of the miniaturists.

mobile phone, thus providing such an

Photo retouching is part of the

ease of use that a large part of the



population often uses these methods.

beginnings. Whether we consider an

Every photo editing software sets its

aesthetic or technical criteria, almost

foundations on traditional methods

the entirety of photographs have had

of photographic copy intervention,

some intervention that has involved a

manipulation and interpretation. In

transformation to a greater or lesser

the middle of the first decade of the

extent of what has been wrongly

21st century, in full development of



the Digital Age, Adobe Photoshop,

understanding of certain actions or

by the ease of access and execution

the software that amateurs and

interventions. Due to the technological

in terms of photographic edition,

professionals most use, continues to

development that makes shooting and

which in turn, has helped numerous

reference back to techniques or tools

obtaining a copy easier, relaxation in

manuals on digital retouching to

used in the dark room for decades.

the technical education which in turn

proliferate in the last decade: i.e.


has ended up in a tendency to focus

Martin Evenning’s on Photoshop for

photographic model, controlled by the

on the project, edition or concept, and

photographers. Manuals that, when

immediacy granted by technology, has

of course on photographic computing,

in the hands of unknowledgeable

resulted in a partly logical distancing

has taken place.

people, who do not know the origin

However, the



of the techniques, can only execute,

from the origins of photographic

These reasons, among others that

production techniques; it is quite

will be analyzed in this work, have

common to find that most people do

generated over the years a confusing

Nowadays, the concept of retouching

not pay attention to the reason behind

and generalized definition that has

has a substantial negative burden,

certain graphic icons. The formative

encompassed a set of techniques and

touched by recurring scandals in

trend in this field does not help much

interventions under the term of photo

the media. A wrongfully understood

in establishing relationships that can be

retouching.This phenomenon, despite


considered of great help for the deep

of not being new, has been extolled

authenticity, the documentary nature,

but with no understanding.





and the history of photography in its Figure 1 • Retouching book in 1895

commercial side, has led to put the term retouching in the eye of the storm. Available




and limited to the late 19th century reference manuals and very few reviews and updates of those in the 20th. During the 21st century, many manuals have been published, but they focus on

Figure 2 • Burning and dodging scheme Figure 3 • Burning and dodging routine

19th century and beginning of the 20th. Another search for manuals on the art of photo retouching in the 19th and 20th century has been performed in the website www. archives.org. [Fig. 1] In Spain, la Biblioteca Nacional (BNEThe National Library) holds some main resources on this matter as well as historic retouched negatives and prints from several archives. At the Instituto de Patrimonio Español (Spanish Institute of Cultural Heritage) we can also find a large number of retouched negatives and prints from its many historic photographic archives.

the current technology and lacking of

that would soon disappear outside the professional field. One of the main reasons for this lies in the difficulty of retouching a 4x5” plate or even more, a 35mm. Pates used professionally were of 4x5”, 5x7” or 8x10” a size big enough to comfortably intervene on it. Smaller negatives could not be printed by contact and they needed the use of an enlarger. The working method for these negatives is rather different from the contact printing due to the following factors: An





between the paper and the negatives,


which will in turn result in a lesser light

them unusable for this research.


intensity especially in the corners.

follows. From the institutional point of view, the Library of Congress website which has allowed us to consult different treatises on photographic retouching dating back to the late

Rubén Morales González

retouching was one of the techniques

any historical reference, which deems The main consulted sources are as


popularization of photography itself,

The light projected onto the paper When in the darkroom, many techniques can be applied to extract all





negative. Due to the miniaturization of the photographic negative and the

can be influenced due to parasite lights from rebounds on the many object present in the darkroom around the enlarger, which will decrease the contrast in the print.

The grain perception and the sharpness sensation decreases as the enlarging factor increases. The projection onto the paper is generally big enough so it can allow to




the paper and the negative, making burning and dodging to extract the maximum information from the negative easier, as well as to obtain the adequate contrast. It also allows softening of the corner’s light falling by what is called “close the print”. All these operations are performed with bare hands, cardboard, play dough or transparent inactinic elements. [Fig. 2] This all means that the print can be worked by areas. Multi-contrast papers allow for different contrast degrees to be used in the same print. [Fig. 3] The actual negative size does not determine the final size of the print or the possibility of making other sizes.

The photographic retouching as a fundamental intervention


It is clear that the enlarging process brings both advantages and

contrary, is performed by scraping the

of the painter, allows for great

Therefore, photography stepped in to

the process, and comparing it to his

emulsion in high-density areas.

possibilities of manipulation with

cover an increasing demand in the first

own portrait on a glass plate, with a

disadvantages comparing to the

Photographers kept their negatives

no technical limitation. Miniaturist

decades of the 19th century: to own

greater depth of field and an almost

contact printing method. Despite

in an archive with the client’s index

from the 18th and 19th century

a portrait as a status symbol. The first

insulting sharpness. Each pore and

the greater flexibility of the enlarger,

card to be retrieved for future copies.

embellished and praised their models

invention commercially exploited was

each wrinkle depicted with no mercy.



Due to the idealization of the portrait

with very solemn poses. These

the daguerreotype; it was an abstraction

It seems this was not of society’s liking,

retouching to continue being part of

obtained in the negative and the

miniatures where mainly directed to

of reality, due to its own specific

judging by the historical evolution of

the process many decades after the

workflow of the time, having a ready-

the emerging middle-class, eager to

characteristics in size, exposure time

photographic studios.

first enlarger appeared:

to-print negative assured satisfactory

imitate the main symbols of nobility.

or finishing techniques. Despite being

As Rosina Herrera, restorer, points

results already approved by the client

One of those symbols was the small

presented as the mirror of memory,

out, the client “[…] started to demand

and in turn save means.

format portrait, which, especially in the

which “returned the viewer the exact

being lied to and for the photographers

the using of graphite and other

first third of the 19th century, tried to

representation of reality, with an accuracy

to embellish reality by the means of

elements applied in both the human


imitate the old miniatures with staged

degree unattainable to painting” , what

traditional techniques, more on the

features and the imperfections to


scenes and vintage dresses, providing

the amalgamated silver showed was

line of drawing and painting”.7

reach the prevailing aesthetic degree.


the portrayed with a higher social

further from reality than many pictorial

There is evidence that photographer

category and ceremony.

miniatures: rictus imperterritus, ghostly

Emil Rabending was the pioneer in



The idealization of the portrait demanded by clients made necessary

This is one of the interventions that cannot be performed when

The Greek beauty canon, accepted

The public presentation of the

looks and an obvious rigidity, portrayed

photo retouching in 1860. He was

using an enlarger and that require

through centuries as the perfect

invention of photography was not by

onto a support that forced the image

highly regarded among bourgeoisie

certain expertise before the printing

aesthetic example has not been

chance. As Publio López Mondejar,

to be viewed from a specific angle,

and nobility. If his success encouraged

process. Dodging in the enlarger is

shared by every culture and has

historian, points out “if photography

which lacked color, and, which size, in


made by applying an inactinic mask

suffered some variations. However, it

had not burst into the scene earlier,

most cases, did not allow for a detailed

among the techniques used, or if it

in low-density areas; burning, on the

has always been present especially in

was because society’s economical


was the clientele, which demanded a

the western society.

and industrial structures were not

Figure 4 • Retouching in a negative






specific finishing in the portrait as the

ready to implement it. Suddenly, after

photography was based in the

Carte de Visite spread out, or both,

manuals, “A Complete Treatise On

half a century of bourgeoisie ruling,

quality and fidelity of reproduction,

the fact is that intervention in the

The Art Of Retouching Photographic

which had opened the door for the

which allowed photography to attain

negative became standard. [Fig. 4]

Negatives And Clear Directions How

economic liberalism and the industrial

a notable degree of perfection in

Due to the critics and controversy

To Finish & Color Photographs”

revolution, it seemed possible to turn

only a few years. A fact that can be

that this phenomenon originated,

from 1898 , takes the Greek canon

that visionary invention into a source

understood as positive was not well

the propagation of this trade was

as model: “The most beautiful mouth

of commercial speculation. […] the

assimilated by the public as they saw

scarce. Even the majority of the few

is generally understood to be of The

technological advancement and the

how their portraits showed reality as

published manuals, concurred that

Greek type, the lines of which follow

increasing political prominence of the

it was. We can all picture a person, in

the best way to learn the profession

the shape of the cupid’s bow “

rising middle-class turned into reality

the 1870’s, looking at his grandparents

was by learning from a retoucher:

what the greater pioneers were

daguerreotype, romantically charged

“The fastest, easiest and best way to

already suspecting […]”.5

with the aesthetical characteristics of

learn how to retouch photographic


the idealization and interpretation

Rubén Morales González



One of the oldest photo retouching

Painting, thanks to its nature and to



Figure 5 • Print without retoching and retouched

The photographic retouching as a fundamental intervention


The origin of retouching lies in a need

popularization of digital photography

of the system itself, that even having


edition; the

being presented as the paradigm of

The term “original” also raises many


technique’s lack of spread on the

a truthful and realistic capture, lacked

doubts not only in the art market

clientele: “some indulgent sitters, to

aimed to embellish or idealize the

one hand, and the ease to access

particular extra photographic aids to

but also in the archival and historical

expertly guidance and even sooner

whom nature has provided with a

portrayed, or even to overcome

and use on the other, have generated

fulfil its goal regarding the technique

terms. The “negative-positive” duality

if you are a natural, you could be a

rather unpleasant face, often demand

specific limitations of the photographic

a combination of terms where the

and the aesthetic. Painting techniques

only makes the consensus more

retoucher. This pamphlet is solely

their portraits to be improved and

system has been around since the

word “retouching” encompass many

were used towards that goal with

difficult. The widely accepted premise

written for those who cannot or do

complying with that needs to be

beginning of photography. As seen

techniques that, at the turn of the 20th

contributions made with graphite,

is that the negative is the original.

not want to learn and train under

avoided. […] It does not work like that



century, were not considered as such.

aniline dyes and other materials, as

Nevertheless, the negative is not

direct supervision of a master, which,

in portraits. No matter how good the

suffered different interventions, all of

Therefore, today’s photo retouching

painting was the closest fine art to

capable of producing a high quality

we repeat, is the fastest and surest

original, people will always think higher

them extra photographic.


print by itself; it cannot be seen

way to learn this trade”.8

of themselves and demand for his

The evolution of retouching has walk

regards of the precepts that were

Even knowing that today’s definition

as a work of art, but rather as an

The scarcity of publications of that

reproduction to be embellished and

hand in hand with the coming of each

accepted since mid-19th century until

of retouching can still be very vague

object. A series of proofing methods

time and later, indicate an agreed

charming (they do not dare say the

new photographic process, which has

the beginning of the 21st century.

there is a noticeable difference

are needed to obtain a final print.

secrecy and shared with the clientele,

word and speak something similar).

led to the existence of some common

The study of photographic objects

between it, and the rest of the

Therefore, in the case of photography

which began to know where they

This feeling prevails especially among

techniques and process-specific ones.

observed during this research work,



the original would be the first print

could be portrayed more favourably.


thus, every photographer

The techniques born from this

clearly define the term retouching



accepted by the printer that will set

Photographic studios were a lucrative

has a retoucher who truly is an artist

evolution have merely become known

as well as its use. Every contribution

are used to extract the maximum

the way to obtain future prints. The

business, though very competitive

that can totally transform a portrait.

with a very limited number of manuals

made on both negatives and prints

amount of information from the shoot

negative thus will be a necessary

due to the large number of them that

But they should not be imitated as,

and papers. One of the reasons to

was done in order to correct

through different means; retouching is

complement of that original and can

were in the cities in different periods.

you should only moderately correct

explain this is the controversy that

the process’ defects, make up for

an outside and idealized contribution

only be regarded as original if placed

[Fig. 5] Cameras, lightning equipment,

nature’s work as it is always superior

certain interventions have always

deficiencies, or to embellish the final

that is placed among the extrinsic

beside the print, because in other case,

emulsions, etc. were the same for

to men’s”.9

arisen, setting retouching as the

print. All of them pursue the same

contributions. In the same way, photo

a different printer could interpret it in

perfect example of the deviation

goal even though the degree of use

techniques have developed with

a different way at any time.

from authenticity of the medium.

of these techniques is varied.

the history of photography while

to not have limits. Some manuals

with those goals which are the

oneself to the training of a good

acknowledge this aspect and implored


teacher. Those ready to do this, will

photographers to put their taste and

not need this book or any other; in

criteria before the demands of the


three months of constant study and

everybody. The photographer made a big difference, but the biggest one of


The origin of retouching, being an photographic




perception is totally distorted with

However, as shown in the study,

them all was the negative retouching.


chapter, other complementary ones

This mystery has upheld until the

negatives or prints is to subjects












unaltered for virtually 100 years

have also arisen:

In the case of a retouched negative, where masks, burnings and graphite contributions have been applied, that

According to what many reference

The proposed objectives of this

retouching was not only accepted


manuals observe in their introductions,

work have led to the execution of

but also demanded by the clientele

development of the negative and

To shed some light and order to

is ready to be printed with no further

more than one retoucher was bound

a thorough historical, technical and

throughout history, like in an idealized

every intervention that comes with

the matter at hand, a typology of

intervention, it could be considered

to surpass the logical limitations of any

aesthetical study both of the examples

and magical aesthetic quest. In spite

it, and it is aimed to chasten defects

interventions has been established

original as these contributions make

artistic process because of competition:

found in different archives and the

of this acceptance, embellishment

or accidents in the developing

to help us discern what should be

any other interpretation of the

However, the clientele, eager to have

reference manuals and books that

methods have been consensually

process and to idealize what is being

considered retouching and what not.

negative difficult. It has to be said that,

a portrait that will not show what

covered this matter. This study has

accepted but hidden from the main

photographed, according to accepted

Besides the conclusions related to

in this case, the photographic negative

the mirror at home showed seemed

produced several conclusions related


aesthetic cannons.

the objectives proposed in the first

along with the retouches forms the

Rubén Morales González


The photographic retouching as a fundamental intervention


NOTAS 1 Measurements are given in inches as it is today’s standard. Correspondent measurements in centimeters are as follows: 8X10”=18x24cm. 5x7”=13x18cm.

original. This kind of mixed originals


can be counted by the millions in

Please note metric measurements do not mathematically correspond with those in

the archives anywhere in the world,

the imperial system; this is because there were two systems that used different plate

as they are the largest part of the known


holders, which were progressively unified from the 1980s on.


2. Negatives smaller than 4x5”, originated from cut plates, have been found during the

They are idealized originals, more or

course of this research, although it is not the general trend. They specifically come

less far from reality and the veracity of

from the Kâulak Archive at the BNE.

photography, but which hold a great

3. (Johnson, 1898) 4. (Johnson, 1898), page 26

importance in history.

5. (Mondejar, 2014) page 1

And it is for this reason, due to its

6. Ídem, page 4

technical, historical and aesthetical

7. (Herrera, 2011) page 112.

importance that a down-to-earth and

8. (Kâulak, 1921).

correct dissemination that will help

9. (Brunel, 1899) page 125.

understand retouching is necessary, no matter the controversies that have followed photographic retouching in its evolution; and of course, to widely circulate and protect an intervention as old as photography itself.

REFERENCES BRUNEL, J. Los fracasos y el retoque. Madrid:

JOHNSON, R. The art of retouching

Librería Editorial de Bailly-Bailliere e Hijos, 1899.

photographic negatives. Boston: American

HERRERA, R. (2011). “Técnicas de retoque de negativos fotográficos: historia y conservación”. Pátina, Vol. 16


Rubén Morales González

Photographic Publishing Co. 1936. KÂULAK, A. C. El retoque fotográfico. Madrid: Libreria Internacional de Romo, 1921.

JOHNSON, R. A complete treatise on the art

MONDEJAR, P. L. El rostro de las letras.

of retouching photographic negatives and clear

Escritores y fotógrafos en España desde

directions how to finish & colour photographs.

el Romanticismo hasta la generación de

London: Marion & Co., 1898.

1914. Madrid: Ediciones del Azar, 2014. The photographic retouching as a fundamental intervention




Nome artigo

Nome artigo


Keywords Pictorial retouching; Colour reintegration; Reintegration criteria;


Lighting sources; Colour temperature; Visual perception.


Beatriz Doménech García María Castell Agustí (1)


| Vicente Guerola Blay



Colour reintegration is a purely aesthetic restoration process that, when carried out improperly, can alter and make the reading of a work confusing.

1. Instituto Universitario de Restauración del Patrimonio de la Universitat Politècnica de València, Camino de Vera s/n 46022 València; beadomga@ gmail.com; vguerola@crbc.upv.es; mcastell@crbc.upv.es

The realization of a good retouching is based on the principles of respect, discernibility and reversibility, as well as on several factors that influence its execution, such as choosing the most suitable materials, the ability and the criterion of the restorer and the quality

Abstract Obtaining a good pictorial retouch depends on multiple factors directly related to its

it is the most similar to natural light

realization. The restorer´s perception influences in colour reintegration and light

and does not provide any additional

is also important in the colour perception. Therefore we can assume the type of


lighting source will be genuinely important during this process, being able to modify


the result of a pictorial retouch. However, restorers do not always consider which


the most appropriate lighting for a retouching is, also ignoring that light may be


warm, white or cold depending on their colour temperature, thus affecting directly

colour temperature and to make a

on the result.


It should not be thought that natural light is the most suitable for chromatic

specimen with distinct illuminations,

reintegration, as it is not a stable source of light. This will vary its colour temperature

in order to establish the chromatic

according to environmental, geographical and time conditions. The best choice


is a stable lighting source that does not change our perception of colour during

perception. This should disclose the

the pictorial retouching process. Thereby, warm light and cool light are discarded

evidence that the type of lighting

because they bring a yellowish tone and a blue tone, respectively, that influences

source is a very important factor to

our perception. That is why white/neutral light is the most suitable lighting since

keep in mind during these processes.

purpose analyse



sources of




several based

types on




is of

their test


of year, the time of day... [6].

of the stucco to be reintegrated [1]. Recent studies reveal that colours are





not perceived in the same way by each

approximate the spectral distribution

individual , because visual perception

of sunlight

also influences on this process



appropriate since they remain stable.

In addition, it has been developed

There are a wide variety of lighting

researches that demonstrate that visual

sources including incandescent, halogen,

impairments also affect chromatic

fluorescent and LED lamps [8]. The last

reintegration [4].

one is the subject of recent studies in


, but they are the most


Based on the theory of colour, we

the field of conservation - restoration

know that light is fundamental in the

because it does not contribute to the

perception of colours

chromatic degradation of the pigments

. However, in


general terms, restorers do not usually


take into account the type of lighting

great diversity, the lighting sources can

sources for the development of a

be differentiated according to their

pictorial retouching, ignoring in many

colour temperature, that is, according

cases that the final result may vary

to a simplified form of indicating the

depending on the use of warm, neutral

predominant tone of a white light,

or cold light.

expressed in Kelvin (K) degrees. Thus,




. It should be noted that, within this


the classification is set in warm light,

considered the optimal light source for

between 2800K and 3500K; neutral light,

the reproduction of colours. However,

between 3800K and 4500K; and cold

it is not normalized since its spectral

light, between 5000K and 6500K [10] (see

distribution varies according to the time

Table 1).

Table 1 • Colour temperature of the light and its corresponding perceived colour tone

Therefore, it is reasonable to believe that the tone of the lighting

chosen, which comprehend in general

this experimental section has been the

the diversity of the chromatic circle:

gouache from Talens® brand, due to its

source can influence the retouching

Lemon yellow ++205X PY3

high hiding power and because, along

processes, so we have proposed test

Scarlet ++334X PR112/PV19

with watercolour, is one of the most

specimens to prove it.

Red violet +++545X PV19/PB29

used in the reintegration of artworks.

Cobalt blue ultramarine +++512X PB29/PB15

In addition, the retouch technique

Green ++600X PX74/PG7

used has been the tratteggio by colour

Burnt umber ++409X PBr7/PBk11

selection, which is made from a selective


Each of them has been reintegrated

colour synthesis (see Fig.1).

experimental section, specimens of

under the three types of illumination,

Regarding lighting sources, LED light

reintegration have been developed in

making a total of 18 test specimens.

bulbs have been chosen because they

distinct colours under warm, neutral

These specimens have been made

are proven to be the most suitable in the

By comparing the test pieces,

and cold light, in order to establish

in white support of Studio Lavis®

field of conservation and restoration. In

differences can be established in the

It is noteworthy that, regardless

with cold light, since they are presented

a comparison between them and

cardboard, with a size of 10 x 10 cm

this practical case, LEXMAN® brand

reintegration of the colours according

of the type of lighting source used,

as the least adjusted colours of the 18

to determine which type of lighting

and it has been reserved a rectangle of

has been used, in the tonalities of the

to the lighting source used.

some colours have presented more

specimens, showing an intervention of

source is most suitable to use during

3 x 7 cm in the central area to execute

warm light of 3000K, the neutral light

Generally, warm light and cold

difficulties or more facilities to be

a tonality little similar to the original

this process.

the reintegration.

of 4000K and the cold light of 6500K

light give to the support a yellowish

able to be adjusted properly. One

colour (see Fig. 4)

(see Fig.2).

and bluish hue respectively, also

of the notable cases is the lemon

Finally, it is important to emphasize

distorting our perception of colours.

yellow colour which, observed for a

the reintegration carried out in

For this reason the specimens that

long period of time, can cause visual

red violet as well, because it is the

intervened with these two types

fatigue, complicating the process of


of illumination mostly have poorly

colour reintegration, especially when

results, regardless of the lighting used.

adjusted reintegration, and may be

intervening with warm and cold light.

This could be explained because its





A total of six colours have been

The paint chosen for the realization of

Figure 3 • Results of reintegration of the eighteen specimens: 1st row, warm light; 2nd row neutral light; and 3rd row cold light.


the visual perception can focus on the

On the other hand, it is remarkable

purity of the colour to be reintegrated

the retouching of the burnt umber

(see Fig.3).

colour with warm light and the green




due to our visual system trying to balance the excess of yellowish and the blue tonality through retouching. Figure 1 • Gouache paints from Talens® brand chosen for the pictorial retouch of the test pieces.

On the contrary, the use of neutral light does not interfere in the same way as the other types of lighting mentioned before. In general, the test pieces present fairly tight pictorial retouching, a fact that can be explained because the neutral light does not provide any type of tonality to the support. Therefore,

Figure 2 • From left to right: warm lighting, neutral lighting and cool lighting.


Nome artigo

Figure 4 • On the left, detail of the result of the reintegration of the burnt umber colour: on the right, detail of the result of the reintegration of the green colour.

Nome artigo


spectrum is midway between cool and warm colours. 4. CONCLUSIONS In general terms, the retouching specimens developed demonstrate that in the reintegration processes it is necessary to take into account the type of light source to be used based on its colour temperature. The use of warm or cold light distorts our perception of colours and provides the support with yellowish and bluish hues correspondingly, with the result that the pictorial retouching is not properly adjusted to the

[1] VIVANCOS, Victoria – La conservación

[7] DE LA ROJA, José Manuel – Sistema de

original colour. Therefore, it can be

y restauración de pintura de caballete: Pintura

reintegración cromática asistido por medios

sobre tabla. Madrid: Editorial Tecnos, 2007.

transferibles obtenidos por procedimientos

deduced that the most appropriate light source is the neutral light, which colour temperature ranges from 3800K to 4500K, because it does not provide any tone that interferes with the pictorial retouch process, nor does it differ in the process of visual perception. Proof of this is the excellent results obtained in the six colours reintegrated through such illumination, since all of them are presented well-adjusted in general. Furthermore, this study is open to



[2] SAUNDERS, David – Retouching: colour

fotomecánicos: aplicación en la restauración

vision and optical considerations. In Conference

de pintura de caballete. Madrid: Universidad

2000: Retouching and Filling. Oxford: Association

Complutense de Madrid, 1999.

of British Picture Restorers, 2000, pp. 3-9. [3] ARNHEIM, Rudolf – Arte y percepción visual. Madrid: Alianza Forma, 2008. [4] BAILÃO, Ana; NASCIMENTO, Sérgio;

lediagroup.com/tecnologia-led/la-temperaturade-color-como-conseguir-el-ambiente-idealcon-lamparas-led/ [12 January 2017].

CALVO, Ana; BRUQUETAS, Rocío – Estudo

[9] LUNZ, Manuela;TALGORN, Elise; BAKEN,

de deficiências visuais para a reintegração

Jannie; WAGEMANS, Wiebe; VELDMAN, Dirk

cromática. ECR - Estudos de Conservação e

– Can LEDs help with art conservation? Impact

Restauro, nº6. Porto: Universidade Católica

of different light spectra on paint pigment

Portuguesa, 2014, pp. 60-89.

degradation. Studies in Conservation.Vol. 62, n.º

[5] MORENO, Teresa – El color. Historia,

future research with distinct types of

teoría y aplicaciones. Barcelona: Editorial Ariel,

paints because, due to their material

S.A., 1996.

characteristics, the retouching results

[6] BRILL, Thomas B. – Light: its interaction

through distinct types of lighting may vary.

with art and antiquities. New York: Plenum

Nome artigo

[8] LEDIAGROUP. Available at: https://

5 (2017), pp. 294-303. [10] MUCHOSLEDS. Available at: http://www. muchosleds.com/es/content/6-temperaturade-color-calido-neutro-frio [11 May 20017].

Press, 1980. Nome artigo


Keywords Chromatic reintegration;


Albumen prints; 19th Century Photographs; Inpainting;

we should know: structure character, materials, •


Albumen print was the most used photographic process in the second half of the Nineteenth Century, especially between 1855 and 1895 . Albumen prints are photographs


with two-layer structure (fig. 1): the

material (silver salts) which reacts easily to any change, especially in the presence of moisture

. For this


need to be aware of alteration factors that could affect this photographic

stability are the most important

Aesthetical characteristics: tonality, reflectance.

criteria for chromatic reintegration,

State of conservation.

always thinking about compatibility

Materials suitable for

between original and added materials. The Gulbenkian’s albums contain

conservation and compatibility. •

for the original. Reversibility and

photographic coatings and

sample of this (about 10%) present

materials used for treatment.

some losses in primary support. As

a part of conservation treatment, we needed to restore the integrity in damaged photographs and we try to test and choose the best option in each case, taking into account the process characteristics and sensitivity.

Object purpose: exhibition, storage and preservation, use etc.

1.2. Treatment purpose

Conservation of Calouste Gulbenkian´s photo albums: •

To restore physical and aesthetical integrity.

1.1. Before chromatic reintegration

To improve and to help the correct image legibility.

in photographs


Solubility parameters in

177 albumen prints and a small

process, taking into account respect

Chromatic reintegration or inpainting

o test different materials

Chromatic reintegration in photographs is an aesthetical treatment directly in original

albums needed a complete study

could be a delicate and controversial

and methods to obtain a

object that aim to fill and recover chromatically missing areas to return the correct reading

and conservation treatment for its

in images. In this case study, different methodologies were applied in two photo-albums

treatment that must always be

recovery and valorization, including

quality results. Asses the

belongs to Calouste Gulbenkian (1869-1955), an important oil businessman and private

the aesthetical context. Some dry


outcome: analysing advantages,

art collector who was founder of Calouste Gulbenkian Foundation in Lisbon (Portugal).

and wet inpainting methods were

These two objects containing numerous medium-large format albumen print and some

tested and compared with the aim

of them with mechanical damages and losses in albumen layer. They have a great value

of interfere as little as possible in

for Gulbenkian ́s history and technical quality as vintage albums, with images of Europe

photographic stability.

and the Middle East belonging to emblematic photographic studies. For this reason, photo-

Nome artigo

Level of sensitivity. opacity, gloss, surface character or

reason, in our treatment choice we


Type of photographic process: coatings, emulsions, etc.

albumen coating with photosensitive

Photograph conservator and Phd researcher. Universidad de Murcia. Calle Santo Cristo, 1, 30009, Murcia (ESPAÑA). albarussa@gmail.com

Calouste Gulbenkian´s albums.

paper support and a very thin binder

Alba Guerrero

to do an inpainting in photographs




conservator-restorer who takes into

disadvantages and risks.

account all the factors, intrinsic and extrinsic, that can influence when making decisions about interventions in original artifacts [3]. When we need

1.3. Diagnosis and general damages

Inadequate environmental factors and poor handling are the most 195

Figure 1 • Albumen print structure

Figure 2 • Loss in albumen print. Paper fibers and cracks are clearly visibles*.

common causes of deterioration in

2.2. Chromatic reintegration medium.

albumen prints: High humidity can

Watercolors, pencils, inks, anilines

cause cracks in albumen layer and

and even, oil pigments, have been

molds, light exposure, contaminants

widely used by photographers during

and bad quality of seccondary supports

the history to retouch final images and

and mounting materials can cause

give the sensation of color that could

fading and yellowing, frequently in the

not be reached in black and white

edges. Bad handling and storage can

photographs . Of course, retouching

cause wrinkles, folds and losses (fig.2).

done by the photographer and


chromatic reintegration do not follow the same principles. The first belongs 2. MATERIALS AND METHODS

to the author or photographer and

Figure 3 • Watercolours, pastels and color pencils tested.

follow restoration criteria. In order

phases, inpainting is one of the

brands previously tested in other

compatibility with isolation layers.

to choose the best option, we test-

last steps. In the two Calouste

scientific studies in the area


Water solubility in watercolours

ed four different mediums and three

Gulbenkian´s albums were necessary

avoid unwanted reactions between

Windsor&Newton do not interfere

brands (figure 3), classified in dry and

a total of nineteenth reintegration

the retouching material and the

with alcohol solubility of Klucel G in

wet methods (table 2). Dry methods

interventions. First, we located the


this layer. This permit to work easily

(color pencils, pastels) do not use

damage photographs and loss area.

water or solvents in their application.

Previously to chromatic medium, we

Wet methods require solvent, in this

need to put on an isolating layer that

Pastels and colour pencils tested

tubes and this is because tubes have a

case water, to be applied and fixed.

was applied to protect losses areas

provided different results. Despite of

big amount of pigments and a greater

We tested two types of watercolours,

and to help treatment reversibility

Rembrandt Pastels have a high quali-

consistency. In shadows areas, waterc-

in tube and pan .

if necessary. In this case, selected

ty like an artistic medium, we are not

olour tubes need less water quantity.

isolating media was a solution with

recommended pastels in photograph.

In any case, humidity is a risk that must



with this medium. In some cases, pan watercolours have less opacity than

3.1. Dry Inpainiting

the other belongs to the restorer. In

2.3. General procedure and

They provide dificult control and

always be weighed. Under prolonged

2.1. Chromatic reintegration process

this case, some considerations have

a cellulose ether in a volatile solvent

inpainting methodology

poor grip on the area and pigment

light exposure, colors could fade.

in photograph lost areas (Table 1).

been based on previous researches,

(4% Klucel-G in ethanol) in order to minimize the amount of moisture in

particles can be easily separated from

photograph. This protection layer also

the isolation layer. Not recommended

acts as a sizing agent on exposed or

in cases where albumen layer is craked

abraded paper fibers

because pigments can be embedded

Table 1 • Steps in chromatic reintegration STEPS

After previous conservation treatment

Table 2 • Inpainting Methods INTERVENTION


Dry Methods PHOTOGRAPH LOST ÁREA LOCATED Localize the missing area (coating loss - primary support). Secondary support, paper in this case, is visible*.

ISOLATING LAYER Protects photograph of inpainting media. Acts as a sizing agent on abraded paper fibers. Increase the reversibility process

Wet Methods

Rembrandt Carré Pastels (Royal Talens)

Windsor & Newton Cotman tube watercolours

Rembrandt Pencils (Aquarell, Lyra Germany)

Windsor & Newton pan watercolours

. If necessary,


we can apply an extra coat. Then, we

Inpainting medium and technique: Watercolour, pastels, pencils, inks... Rigattino, tratteggio, puntello... Finished technique: Ágata, Teflon burnisher, final coatings...

Albumen prints are very sensitive materials, above all in high relativity

and remained permanently. Colour pencils LYRA Rembrandt

humidity conditions. If wet

selected media (fig. 4) and more

can apply totally dry, do not add

are used, is desirable to limit as much



humidity to photography and this is

as posible the use of water. Despite

in each case (rigattino, tratteggio,

an advantage. They are water soluble

with watercolours is easier to get

puntello etc.). Finally, improve the

and if necessary, give the option to

the desired color, in mostly cases

results and modify the surface

work dry/wet. Also, allow a glossy

with color pencil had good results

character according to photograph.

finish with a burnisher. Sometimes is

without the need to use water.

In some cases, we need to increase

difficult to achieve the desired shaded

Results presented here may not be

gloss with a Teflon burnisher

with dry methods, especially in light


areas. Light stability of some colors

case. They have been based on the

has been questioned.

author’s experience, experimental





and scientific
researches in similar In all cases, we try to use reintegration materials for inpainting and

Alba Guerrero


proceed to color reintegration with



Figure 4 • Chromatic reintegration in a photograph with colour pencils.

studies mentioned

3.2. Wet inpainting

Wet methods tested have a high

For a more


substantiated results, we need to

Chomatic reintegration in late 19th century albumen prints


do specifical
research and technical analysis about inpainting materials and long-term reaction
 between compounds



chemistry. Conservation treatments must be preceded by a previous research of materials used and then, a subsequent

monitoring of

environmental conditions in storage, light exhibition parameters and avoid long exposure periods.

REFERENCES [1] LAVEDRINE, Bertrand, Photographs of the past: Process and preservation, Los Angeles:Getty Conservation Institute, 2009.




Inpainting Outline, Photographic Materials

co.uk ltd., 2010.

Group Catalog, AIC, Wasingthon D.C., 1994.

[4] NORRIS, Debra Hess, Gutierrez, Jae.

[7] AIC WIKI. Photographic Material. PMG


Issues in the conservation of photographs. Los


on photographs: materials, techniques and

Angeles: The Getty Conservation Institute,

Procedures: Inpainting. Available at: http://

conservation. Washington, DC: American


www.conser vation-wiki.com/wiki/

Institute for Conservation of Historic and Artistic Works, 2005. [3] APPELBAUM, Barbara - Conservation 198

Treatment Methodology, London: Amazon.

Alba Guerrero

[5] WILCOX, M. The Wilcox Guide to the Best Watercolor Paints. Perth: Artways, 1991. [6] NORRIS, Debra Hess (compiler) et al.




PMG_Inpainting#4.4_Inpainting_Media [28 January 2017].

Nome artigo


Keywords Selective removal; Underpainting;


Isolating Varnish; Retouching; Final Varnish 2. METHODOLOGY In order to determine if layered systems of retouching used in The

In the Easel Paintings ConservationRestoration Studio of The Arts Academy in Split, a number of different materials have been used over the years to reconstruct losses in the paint layer. Usually, a layered system of retouching is employed, consisting

Sagita Mirjam Sunara | Dorotea Krstić ^

University of Split, The Arts Academy, Conservation-Restoration Department; Fausta Vrancića 17a, 21000 Split – Croatia; E-mail address: sagita.sunara@gmail.com; dorajure@yahoo.com

of underpainting, isolating varnish, final layers of retouching and final varnish. During the layering process, special care is taken to ensure that the medium does not resolubilise the lower layer or layers. Whether it will be possible selectively to remove the added layers in the future is rarely taken into consideration. It would be highly beneficial if one could, for

Abstract Layered systems of retouching used in the Easel Paintings Conservation-Restoration Studio of The Arts Academy in Split (Croatia) are analysed. A critical evaluation of the possibility of selective removal of individual layers from the top down is given. The evaluation is based on the data on the solubility of the resins used for

example, remove the final varnish without disturbing the final layers of retouching, or remove the final layers of retouching without damaging the isolating varnish. As a par t of Dorotea Krstić’s

the preparation of varnish and of the materials used as paint binders, which was

master’s thesis, in 2016 a project

collected from the existing literature. The research showed that selective removal

was initiated that aims to: 1)

of layers with the use of pure solvents is possible in only one of the six systems

create a char t enabling the easy



1. INTRODUCTION comparison of the solubility (and compatibility) of different materials used in the layered system of retouching, and 2) design layered systems









removal of their constituents. This ar ticle focuses on the first phase of the project: the analysis of the materials used in the Easel



Restoration Studio of

The Ar ts

Academy in Split, and a critical evaluation of the possibility of their selective removal with the use of pure solvents. In the following phase a bibliographic study will be conducted of the materials generally used in layered systems of retouching. The possibility of their selective removal with solvents will also be evaluated. In the last stage of the project, layered systems of retouching will be proposed in which layers can be selectively removed from the top down.




Conservation-Restoration Studio can be removed selectively, the first step was to identify the materials that were used. The information was collected from the printed documentation stored in the Studio’s archive, which encompassed the period from 2002 to 2017. It should be noted that all the paintings included in this survey were done in oil. The data were presented in the form of a table providing information about the artwork (artist’s name, title, date of creation, owner/location) and the materials used for each of the layers in the system: underpainting, isolating varnish, retouching and final varnish (see Table 1). The data were sorted in chronological order, starting with the first painting treated in the Studio (the treatment was completed in 2002) and ending with a painting whose treatment has been completed very recently (in 2017). This enabled the use of different materials to be tracked and certain trends to be established.








10 % solution of Paraloid B72 in toluene


Pigments bound with Canada balsam




16 % solution of dammar in turpen tine



Acrylic paint



Anonymous Venetian painter, Flagellation of Christ, 17th century, Parish house of Holy Cross Church, Split




Table 3 • Solubility of the materials used in the layered system of retouching No. 2


Table 1• An example of a layered system used in the Arts Academy’s Easel Paintings Conservation-Restoration Studio

Final varnish: Paraloid B72 Retouching: Mastic Isolating varnish: Dammar

the data collected from the literature



resins used for the preparation of

were presented in tables. Next, the

retouching, and final varnish. For

varnish and of the materials used as

solubility of the materials in each of the

each layer, a table was created that

paint binders were collected from the

layered systems used was compared.

includes the following information:

existing literature.

For ease of reference, tables were used

material, comments (for example, the

sources provide information on sample

concentration of a varnish solution),

preparation , but those that do indicate

the year in which the treatment was

that solubility testing was performed on

completed and general information

freshly prepared samples. Only Horie

about the artwork.

gives information on solubility of aged



Not all of the

to present the data.

dammar and mastic.


Final varnish: Paraloid B72


Retouching: Canada balsam

Underpainting. The types of paint

Retouching: Canada balsam Isolating varnish: Paraloid B72 – Soluble

– Borderline or partially soluble












Final varnish: Dammar

– Insoluble

Isolating varnish: Dammar

used were watercolour, gouache,

No practical

Table 2 • Solubility of the materials used in the layered system of retouching No. 1

Sagita Mirjam Sunara | Dorotea Krstić

Table 4 • Solubility of the materials used in the layered system of retouching No. 3


The final step was critically to evaluate


– Borderline or partially soluble


First, the data on the solubility of the

– Soluble


materials for each of the four layers:

– Insoluble


of our research. For easier comparison,


individual layers in the systems used.


chronologically the use of specific


tests have been carried out as a part


the possibility of selective removal of


The next step was to present

– Insoluble

– Soluble

– Borderline or partially soluble

tempera and acrylic. The most

paint were used for final retouching,

prepared with the use of Canada




balsam as binder. That paint was used

watercolour: it was used on 16 out

by the mixing of pigments with a

on 17 out of 24 paintings. Pigments

of 26 paintings.



bound with Paraloid B72 were used

Isolating varnish. Paraloid B72 and

Paraloid B72 and MS2A were used

for the retouching of four paintings.

dammar resin were used for the

as binder materials. Occasionally, pre-

In the other three cases, Maimeri

preparation of an isolating varnish.

mixed paints were used: Maimeri

Restoration Colors, watercolour and

Dammar varnish was used on 11 out

Restoration Colors (binder: mastic

MS2A-bound paint were used.

of 21 paintings. Paraloid B72 varnish

resin) and watercolour (binder: gum

Final varnish. Paraloid B72, dammar

was used in the remaining 10 cases.

arabic). The most commonly used

and Regalrez 1094 were used for the

materials for retouching were paints

final varnishing. Paraloid B72 was used




Final retouching. Several types of




binder. Canada

Selective removal of layers in layered systems of retouching: a research project in progress













Table 5 • Solubility of the materials used in the layered system of retouching No. 4

Final varnish: Paraloid B72 Retouching: Canada balsam Isolating varnish: Paraloid B72 – Insoluble

– Soluble

in 15 of 19 cases. Dammar varnish

described in professional literature,

was used on three paintings, while

and to propose reversible layered

Regalrez 1094 was used only once.

system(s) of retouching for oil paintings,

Our research revealed that six layered systems of retouching were employed.

Further research should focus on

Solubility of the materials used is

finding a system – or a method of

presented in Tables 2 – 7. Information

application – that meets specific

on materials used in underpainting has

aesthetic requirements (saturation,

not been included because solubility

gloss etc.).


– Borderline or partially soluble

either new or those already in use.




isolating varnish generally differ (acrylic paint presents an exception). It should be noted that in several WHITE SPIRIT






cases final varnish was not applied. ETHANOL





Table 6 • Solubility of the materials used in the layered system of retouching No. 5

Final varnish: Dammar

separately because their constituents match those presented in the tables shown on previous pages. 3. CONCLUSIONS

Retouching: Canada balsam Isolating varnish: Dammar

The information collected allowed – Insoluble

– Soluble

– Borderline or partially soluble


the systems that have been used so

Ronald – Strip ‘Teas’ – solubility data for the

far enable the selective removal of

removal (and application) of low molecular

Canada Balsam. Available at: http://shop.

weight synthetic resins used as inpainting



[5 December 2015].







that selective removal of layers is possible in only one of the six systems used (system No. 3). In three systems one might at best be able to remove the varnish and retouching without

Final varnish: Regalrez 1094

damaging the isolating varnish (system

Retouching: MS2A

No. 1, 2 and 6).

Isolating varnish: Dammar – Insoluble

Sagita Mirjam Sunara | Dorotea Krstić

– Soluble

– Borderline or partially soluble


conclusions to be made as to whether

individual layers. The data indicate ETHANOL





Table 7 • Solubility of the materials used in the layered system of retouching No. 6


Such systems are not presented

The next step of the research is critically to evaluate the systems





Association of Art Conservation Newsletter, Vol. 30, n.º 1 (2008), pp. 11–19.





[5] WHITTEN, Jill; MENTION, Elisabeth; Merz-Lê, Liisa; Barach Cox, Ruth; Fisher,

[2] GETTENS, Rutherford John; STOUT, George

Sarah L.; McGinn, Mary; Proctor, Robert; Van

Leslie – Painting Materials : A Short Encyclopedia,

Vooren, Camilla; Swicklik, Michael; Berger, Mira

New York: Dover Publications, 1966.

& Gustav – Low Molecular Weight Varnishes

[3] HORIE, Charles Velson – Materials for

(1997). AIC Wiki website. Available at: http://

Conservation : Organic Consolidants, Adhesives


and Coatings, London; Boston: Butterworth-

Molecular_Weight_Varnishes [5 December

Heinemann, 1987.


Selective removal of layers in layered systems of retouching: a research project in progress


Keywords Sappho Fresco


Painting reconstruction

were used as a reference. Where

Ancient pigments

traditional pigments were hard to obtain, due to their toxicity and/or

Roman art

price on the market, contemporary substitutions were applied (table 1). [1] According to historical sources and published technical studies

buon fresco, where pigments, due to the The Pompeian medallion portrait Archaeological Museum, is one of the most precious paintings of the Italian

several cutaway sections, in order to

carbonation of lime, form a permanent

observe the textures, the transparencies

bond with the plaster. Unlike the

and the brush strokes at every stage of

original approach, the reconstruction

the reconstruction process.

featured both buon fresco and fresco secco methods.Those methods gave an

cultural heritage. This is essentially related to the eruption of Mt. Vesuvius that destroyed the Pompeii in 79 A.D.

1. 2.

Arts Academy of the University of Split (graduate student), Zagrebacka 3, 21000 Split - Croatia; lenaboskovic3@gmail.com Arts Academy of the University of Split, Zagrebacka 3, 21000 Split - Croatia; sansustic@gmail.com

The excellent preservation state of the ruins allowed the investigators to examine the original fresco techniques directly on the ancient Pompeian yard, where the lava flow saved the frescoes from loss. [1]


interesting insight into the application methods of the same paint on a

Since no accessible information

different kind of ground.

were found about the original type of the plaster or pigments applied on


Sappho, the traditional Roman lime


plaster recipe as well as the pigment

Although originally a wall painting,

palate available in Roman period

the reconstruction was prepared on a

Based on the published research results and historical sources, a reconstruction of the Sappho has been


made. The primary intention of this practice was to analyse the Classical

Among several of survived painted portraits from Pompeii there is one small but famous painting known as the Sappho - Girl with Stylus and Tablets - most likely created around 50 AD and found in the house of the Insula Occidentalis. This work is related to the reconstruction of Sappho and it aims to investigate the Classical Roman painting techniques and working methods. Historically informed materials were used in the process but with a modern modification - a XSP was placed as a support, instead of the wall.

, the


paintings of this period were made in


known as the “Sappho”, now in Naples

Marija Lena Bošković (1) | Sandra Šustić (2)






working methods. Correspondingly, this project also enabled to practice skill development necessary for future work in retouching. With accordance to the educational

It is hoped that this study will enable a better understanding of fresco painting

purpose of this project, the stratigraphy

techniques, thus facilitating working methods for future retouching projects.

of the painting was left exposed in

Table 1 • Pigments used in reconstruction of the paint layer

portable fresco panel made from XSP.

with umber pigment mixed with lime

softened where needed with the

would become partially smudged

to observe how a pigment behaves

With the aim to achieve optimal plaster

water as binder (Figure 1). The same

semi-dry and clean brush (Figure 4).

or erased. Thus it was necessary to

in lime water as binder and how the

adherence, the surface of XSP was

paint was used in underpainting.

restrict the amount of lime water and

degree of dryness of the plaster

match the necessary tone in only one

effects the working properties and

brush stroke.

the final appearance of the paint layer.

evenly scratched. The roughcast was

Figure 1 • Sinopia

Figure 2 • Sappho after buon fresco method (note the blackening of azurite).

Figure 3 • Applying Fresco Secco method


Marija Lena Bošković | Sandra Šustić


made of lime and white sand particles of


3-4 mm in the 1 to 1 ratio with addition


The use of azurite demonstrated the

This reconstruction demonstrates

of water, and spread over the surface.

The reconstruction of the paint

that achieving a perfect ratio between

The layer was less than 2 cm thick, and

layer was initiated while the plaster

the lime water and sand during the

of a volume of cca 1,2 L. Decision not

was still moist. Due to the process

plaster preparation may not be a

to apply the second layer of the plaster

of carbonization, the paint formed a

was made. This was to prevent the

importance of understanding of the


paint components which is essential an

for any reconstruction and retouching

straightforward task - the formation

interesting insight into the working

to work well. This requires a great deal

firm bond with the plaster. Slowly and

of the small drying cracks can be

process of Classical Roman painting

of study of the paint structure to find

fracture of the painting caused by the

precisely the chiaroscuro was build

a common incidence. The most

techniques and working methods. The

out the pigments and binding media

excess weight. The preparatory sketch,

using a soft brush. The transparency

interesting part of this process was

primary intention of this project was

present. It is hoped that this study will

imitating sinopia, was carried out with

of paint was adjusted by varying the

to observe how the paint behaves on

charcoal and umber.

amount of lime water. After the plaster

slightly wet intonaco – the appearance

Next, the intonaco, a coat 5 mm

was completely dry the painting

of the brush strokes was extremely

thick was applied after ariccio was

process was continued with fresco

light and smooth tonal transitions

almost completely dry. It was made

secco technique which required much

were easily achieved. While applying

of fine sand from the town Turjak

more attention: it was necessary to

various pigments on a wet alkaline

in Croatia with size of the particles

apply only the thick paint with brush

environment, a special attention needs

less than 2 mm. The sand was mixed

strokes, otherwise the brush would

to be given to the consequent pigment

with lime in ratio 2:1,5, making its

erase the paint beneath.

reactions; azurite, used in the mixture

volume around 6,7 dL. Since Sappho

It is important to emphasize that

for painting the sky area, started to

is rather small painting, the decision

the application of azurite in the sky

tarnish after the paint dried, resulting

was made to cover the whole surface

area resulted in blackening caused

in overall discoloration. Namely due

with this layer which is opposed to

by chemical alterations (Figure 2).

to the presence of alkaline conditions,

the traditional practice in which the

Accordingly, it was necessary to

azurite has transformed to copper

intonaco is applied exclusively to

repaint this layer with another one

oxide (tenorite: CuO).[4]

those areas which are expected to be

that has excluded azurite (Figure 3).




Figure 4 • Reconstruction of the Sappho painting

The transparent and smooth brush

painted in a single session (giornata).

The last step in the reconstruction

strokes, easily achieved in buon fresco

Consequently, the sketch of sinopia

process was to paint the highlights

technique, were replaced with the

couldn’t be used as a guideline, so

which are present on the hair

thick ones during fresco secco. The

it had to be repeated. The spolvero

ornaments, the curls, and the drapery.

application of transparent paint layers

technique was used for this purpose,

They were painted when the surface

turned out to be very destructive for

while the composition was traced

was entirely dried. Sharp edges were

the dried paint beneath - the color

Reconstructing of the Sappho painting towards abetter understanding in retouching


enable a better understanding of fresco painting techniques, thus facilitating working methods for future retouching projects.

REFERENCES [1] DURAN, A. et.al. - Determination of

Roman wall paintings in the Vesuvian area.

colours in Roman frescos. Available at: http://

pigments and binders in Pompeian wall

Journal of Raman Spectroscopy,Vol. 41, (2010),


paintings using synchrotron radiation – high-

pp. 1537-1542.


resolution X-ray powder diffraction and

[4] MATTEI, E. - Raman spectroscopic

conventional spectroscopy – chromatography.

analysis of azurite blackening, Journal of Raman

Archaeometry Vol. 52, n.º 2 (2010), pp. 286–

Spectroscopy, Vol. 39 (2008), pp. 302–306.

April 2016]. [7] Sappho from Pompeii. Website with the data of the Sappho painting. Available at:

[5] Natural Pigments. Official website of an


[2] Vitruvius, in Morgan, M. H. (ed. - De

art supplier Natural Pigments. Available at:


architectura libri decem, II (materials) and VII


pompeii [17 April 2016]

(finishes and colours), Kessinger Publishing,


Whitefish, 2005.

[17 April 2016].


[3] ALIATIS, Irene et.al. - Pigments used un



Nome artigo

[6] Decoded past. Website of the use of

Nome artigo


Keywords Black-light paintings; Colour reintegration;


Serena Francone (1) | Silvia Bruni (2) | Chiara Zaffino (2) | Katia Galli (2) | Vittoria Guglielmi (2) | Maddalena Boscacci (2) 1 Freelance Conservator of Contemporary Art; viale Kennedy 2, Bregnano (Como, Italy); E-mail address: materiadarte@gmail.com 2 Department of Chemistry, Università degli Studi di Milano; via C. Golgi 19, Milan (Italy); E-mail address: silvia.bruni@unimi.it

between the time of painting creation

Fluorescent pigments;

and the present in which conservation


work occurs. Thus, we should always recognise the aesthetic conservation

Non-invasive analyses;

treatments on a perceptual level.

Raman spectroscopy.

This is possible thanks to a technical differentiation




chromatic selection) and also in the case of mimetic retouching, in which


the intervention is visible under UV 1.1 Mario Agrifoglio’s black-light

with different fluorescent properties.

light. But in the retouching of Agrifoglio’s


Thereby,Agrifoglio was able to achieve


a completely unexpected aesthetic

would compromise the aesthetic

effect that was variable under both

message both under visible light and

visible and UV light. His paintings

UV light. Thus, to maintain the same

question the common understanding

appearance in the retouched areas,

of additive and subtractive synthesis

we must use the same pigments of

and deepen the phenomenon of

the original paint layers. Consequently,

metamerism, which becomes the

a new methodology for retouching,

protagonist of his art.

which shift the recognisability of the

The Italian artist Mario Agrifoglio (1935-2014) was one of the first to systematically use fluorescent paints in the creation of his artworks. He started painting very young, developing an interest in techniques that focused on the exploration of light and colours. After discovering Wood’s lamp





paintings with a geometric-abstract style




The paintings were made in a dark room with a super-fine control of mixtures and overlapping materials


treatment to a different level from the

during a collaboration for a work of restoration, in the early 1970s


1.2 Conservation Issues

perceptual one, should be defined.

As Cesare Brandi wrote in his “Theory of restoration”

, lacuna treatments


1.3 Aims

are primarily a theoretical problem.

Fiber Optic Spectroscopy both in

Retouching should be recognisable to

Reflection (FORS) and in emission

respect the authenticity of the artwork

and XRF spectroscopy were already

and also to maintain a distance

performed on the artist’s paintings

Abstract Mario Agrifoglio’s black-light paintings raise specific issues in case of colour reintegration.

pigments used by the artist with precision, Raman Spectroscopy, both normal and surface-enhanced (SERS),

Metamerism is central in the works made by the artist since the 1970s: according to

was used. Analyses were performed on samples of old vinyl paints taken from three containers found in

the type of light source, the perception of colours of his geometric-abstract paintings

Agrifoglio’s studio. Raman spectra were then compared to those obtained by the analyses made on samples

changes considerably. The identification of materials and techniques used becomes

of new paints of the same brand used by the artist. The results showed a significant similarity between the

fundamental to define how to retouch Agrifoglio’s paintings without altering their

old and the new paints. Moreover, it was possible to identify the main components responsible for the colour

appearance, neither under visible light nor under UV light. To characterise fluorescent

in each paint, in particular copper phthalocyanines for blue and green and rhodamines for red and orange.

White B001




Figure 1 • The eight colours of new “Flashe Fluo” by Lefranc & Bourgeois, analysed and compared with the old ones from the 1990s.

but were not enough to

([2], [3], [4])


characterise the fluorescent pigments. To achieve this goal, it was decided to perform Raman spectroscopy on samples of fluorescent paints, as previous research in scientific literature






technique able to identify the nature of fluorescent organic pigments ([5], [6]). The





Agrifoglio as fluorescent colours are “Flashe Fluo” vinyl paints by LeFranc & Bourgeois. Fluorescent pigments are fluorescent dyes dissolved in a carrier

Samples of old “Flashe Fluo” paints (red 376, blue 029 and white 001) were taken from three containers dating back to the 1990s, found in the artist’s studio. They were painted on an industrially prepared canvas panel, near samples of new “Flashe Fluo” paints of the same hues. Other samples of all the eight colours of new “Flashe Fluo” (Figure 1) were painted on another canvas panel.

Enhanced Raman (SERS) spectroscopy.

connected by fibre optics with two laser sources (l = 532 and 785 nm) and with an Oriel MS125 spectrometer equipped with an Andor CCD detector. FT-Raman spectra were recorded by a Jasco RFT-600 spectrometer (l = 1064 nm). For SERS measurements a silver colloid prepared according to the Lee-Meisel procedure was employed. Further analyses were performed by combining a separation technique like Thin Layer Chromatography (TLC) and



dyes (Figure 4). In case of Blue 029 and White 001, brighteners act as

Optical brightener BASF Tinopal OB

fluorescent pigments.

Figure 3 • The FT-Raman spectrum allowed the identification of the optical brightener constituting White 001. The bands of the brightener are observed together with those of the melamineformaldehyde p-toulensulfonamide resin contained in the pigment.

SERS. TLC separations were executed on silica plates with aluminium support and a mixture of 2-propanol-acetoneammonia 22:1:2 as eluent.

with reference materials.The main dyes identified for each colour are reported in Table 1. Different colours are the result of different mixtures of dyes. For


example, Red 371 and Red 376 are different for a lower content of

Analyses carried out on old samples of “Flashe Fluo” paints showed no difference in composition compared to the new ones (Figure 2). Raman and SERS analyses on the samples of the new “Flashe Fluo”

carrier resin at a rate of 1-4%, but their

Solvent Yellow 160:1 in Red 376. Reds and orange are characterised by the presence of rhodamines B and 6G, while in blue and green there are copper phthalocyanines, that are not fluorescent, but they are put together

paints highlighted the presence of a

chemical compositions are usually not

polyvinyl acetate binder (as confirmed

published in order to maintain trade


Pigments contained in the paints are

dyes in paints constitutes the greatest

composed of a melamine-formaldehyde

obstacle for their identification. as objectives: check differences in the composition between old samples of “Flashe Fluo” vinyl paint found in instead of characterise the chemical Figure 2 • Comparison between FT-Raman or FT-SERS spectra acquired on samples of three hues of old “Flashe Fluo” paints and the new ones.

Serena Francone | Silvia Bruni | Chiara Zaffino | Katia Galli | Vittoria Guglielmi | Maddalena Boscacci

Rhodamine B, Rhodamine 6G, Solvent Yellow 160:1 Rhodamine B, Rhodamine 6G, Solvent Yellow 160:1

Red 376

3) in which are dissolved one or

Red 435

Rhodamine B, Rhodamine 6G

more dyes in different proportion.

Orange 232

Also, brighteners and non-fluorescent

Rhodamine B, Rhodamine 6G, Solvent Yellow 160:1

Yellow 173

Solvent Yellow 160:1

colours.The identification of these dyes

Green 590

Phthalocyanine green PG7, Solvent Yellow 160:1

was done through SERS after TLC

Blue 029

Phthalocyanine blue PB15


separations, thanks to the comparison

White 001




organic pigments can be found in some

the artist’s studio and the new ones

Red 371




The use of Raman spectroscopy had

Figure 4 • TLC analysis (observed at 365 nm) of Blue 029 in comparison with some commercial optical brighteners. Blue 029 is the last on the right.

Table 1 • Dyes identified in “Flashe Fluo” paints

by the IR spectrum).

secret protection. The low amount of



RMP-100 microprobe (50x objective)

Fluorescent dyes are dissolved in the

fluorescent colours sold by the brand.


* Bands due to resin

Raman spectra were acquired by a Jasco

resin and ground into a fine powder.

composition of each of the eight



The analytical methods used in the present work were Raman and Surface-

FT-Raman spectra (�exc=1064 nm)



The issue of metamerism in Mario agrifoglio’s paintings. Identification of fluorescent pigments through raman spectroscopy to define a methodology for retouching.


4. CONCLUSIONS The analyses carried out allowed to recognise the organic dyes contained in each fluorescent colour of “Flashe Fluo” vinyl paints by Lefranc & Bourgeois.The comparison between the old samples of paints and the new ones showed that the same components were kept by the brand during time. Fluorescent pigments are produced especially by Chinese and Indian companies and then bought by fine art manufacturers, which add them to specific binders. In this research, it is very important to know which dyes are contained in pigments, as only the same mixtures give the same fluorescence. The painting technique of Agrifoglio is very sophisticated and is based on an in-depth study of aesthetic effects obtained




fluorescent paints and non-fluorescent paints. So next steps of research will be focused, on one hand, on the study of the chromatic effects obtained through the layering of different paints, and on the other, on the selection of a binder for retouching with different

[1] BRANDI, Cesare – Theory of restoration, Torino: Einaudi, 1977, pp. 71-76. [2]

Congress IGIIC “Lo Stato dell’Arte”, Academy







(in Italian). Proceedings of the XIV National





of Fine Arts of L’Aquila, 20-22 October 2016. Nardini, 2016, pp. 443-449. [4]


Agrifoglio. Study of the technique and material




Lorenzo; LUDWIG, Nicola – Mario Agrifoglio’s

analyses. In SELVA BONINO, V. Emanuela,

Convergenze. Conservation issues of black-


all’acrilico, dall’Impressionismo

light paintings. ICAR journal no.1, Academy of

all’arte contemporanea, proceedings of

Fine Arts of Warsaw, Poland, 2017, pp. 98-109.

the VII International Congress “Colore &

[5] COLOMBINI, Alain; KAIFAS, Delphine –

Conservazione” organized by Cesmar7,

Characterization of some orange and yellow

Politecnico of Milan, 13-14 November 2015.

organic and fluorescent pigments by Raman

Il Prato, 2016, pp. 272-273.

spectroscopy, IRUG08 conference, Vienna,





chemical and physical properties than


the original paint layers. In this manner,




recognisability will move from a

Lorenzo; LUDWIG, Nicola – A red of all

– Characterization of daylight fluorescent

perceptual level to a chemical/physical

colours: analyses of the painting technique

pigments in contemporary artists’ paints by

by Mario Agrifoglio and considerations on

Raman spectroscopy, IRUG11 conference,

the retouching of the black-light paintings

Boston, 2014.







Serena Francone | Silvia Bruni | Chiara Zaffino | Katia Galli | Vittoria Guglielmi | Maddalena Boscacci

Nome artigo


Keywords Religious paintings; Archival photos; Complete polychromy reconstruction;


Maimeri® restoration colours; Gloss of retouching colours; Retouching techniques.




of paintings that are displayed

Lana Kekez (1) | Kristina Krivec (2) | Julija Baćak (3)

in churches and are a subject of veneration usually requires a complete reconstruction of the

1. Freelance conservator, A. B. Šimića 32, 21000 Split - Croatia; lanakekez@yahoo.com 2. Freelance conservator, Put Brda 27, 21000 Split - Croatia; krkrivec@gmail.com 3. Freelance conservator, Kukuljevićeva 10, 21000 Split - Croatia; julijaenator@gmail.com

missing parts of the polychromy. The conference poster presented three examples of conservation treatments performed on 18th century easel paintings with different types of damage and loss to their polychromy. The decisions on the conservation


Figure 1 • The ‘Saint John the Baptist’ painting before and after the treatment

treatment and materials were based

Maimeri® restoration colours[2] for

on the condition of the paintings and

retouching when applied on top of

the study of the available archival

two different isolating varnish layers

documents as well as the authors’

(Paraloid™ B72 and dammar), and

experience in the field. Decisions

3) to understand which retouching

regarding reconstruction of the

techniques are most suitable to match

missing parts of the polychromy

the texture of the original polychromy,

were thoroughly discussed with the

blending the reconstructed areas with

owners and the representatives of

the surrounding original in each case.

The authors present case studies in which a complete reconstruction of the missing

or Paraloid™ B72). As expected, the

and damaged parts of the polychromy of three 18th century paintings was carried

colours were semi-glossy to matt

out. This approach was chosen because of the paintings being displayed in churches


where they were the objects of daily veneration. The complete reconstruction of

retouching colours matched that of

the missing and damaged parts of the polychromy was based on a comparison with

the Paraloid™ B72 varnish, excluding

the conservation treatment funding

the preserved parts of the paintings and in one case on archival photos taken prior

the need for additional medium. In

program (art historians) [1].

to the damage.

cases where dammar was used as an

In all three cases, mastic based Maimeri® restoration colours were used for

isolating varnish it was necessary to

the retouching. Different retouching techniques (pointillism, tratteggio or a

add some extra dammar solution to

combination of various graphic forms) were used to blend the reconstructed areas

the retouching colours, especially in

with the surrounding original. The authors empirically analysed the gloss of the

the darker areas of the polychromy.

retouched areas, depending on the type of underlying isolating varnish (dammar







The aim of analysing these three examples was: 1) to compare the

The 18th century altar painting on

sources on which the polychromy

wood, representing Saint John the

reconstructions were based, 2) to

Baptist, belongs to the old parish

study the gloss of the mastic-based

church of Saint Anthony of Padua in

Svib (Croatia), a little village in the

Plextol® B500 and Tylose® MH300

Dalmatian hinterland, and is a part

based filling was toned to match the

of the main altar ensemble together

original wood.

significant loss of the canvas and the

found in the Photo Archive of the

penetrating into the painting, and the

polychromy, especially in the area of

Split Conservation Department of

The 18th century altar painting on

high moisture sensitivity of the canvas

the Virgin’s nose. Old black and white

the Ministry of Culture [3]. They show

had led to its degradation and to a

photos taken in October 1987 were

the painting prior to its degradation

with a similar painting of Saint Michael.

The retouching process demanded

canvas, depicting Virgin Mary and Child,

Both paintings were overpainted at

a complete reconstruction of the mis-

is kept in the niche of the main stone

some point. The original compositions

sing parts. Since there was no photo

altar of the cemetery church of Saint

showed the scene of the Annunciation:

documentation showing the painting

Anne in Šibenik (Croatia).

the Angel Gabriel was painted on what

prior to the burning, the reconstructi-

The painting was found loosely fixed

is now the ‘Saint John’ painting and the

on was done by analogy with the pre-

to an improvised wooden backing and

Virgin was painted on what is now the

served parts of the polychromy. In the

subsequently placed in a wooden box

‘Saint Michael’ painting. The original

underpainting only the basic shape

which was completely degraded by

paint layer was applied directly to the

and position of the leg, shoe laces and

moisture and microorganisms. A red-

wood surface, without any ground

cross were defined. All the details and

toned ground layer had been applied

layer. It was later overpainted with the

the background were reconstructed

to the surface of the sparsely woven

existing paint layer showing Saint John

in the final retouching. Since the pain-

canvas. The adhesion between the

and Saint Michael, and varnished. The

ting style was quite naive, Saint John’s

polychromy and the canvas was only

‘Saint John the Baptist’ painting was

right leg was symmetrically transfer-

locally weakened. Losses to the paint

severely damaged by candle flame.The

red, using a transparent foil. Saint Mi-

layer mostly corresponded to the

whole lower right part of the image

chael’s legs, posed in a similar manner,

damaged areas in the canvas (Fig. 2).

was destroyed, including Saint John’s

served as a model.

leg, cross and background (Fig. 1).


High humidity in the stone altar niche


Figure 2 • The ‘Virgin Mary and Child’ before conservation

Considering the characteristics of

Several examination methods were

the original polychromy (light and

performed such as the stratigraphic

relatively matte) and reversibility

analysis of the polychromy and

questions, 15% Paraloid™ B72 in

X-ray radiography. Solubility tests

toluene was applied as an isolating

of the varnish and the overpaints

varnish layer. On top of it, retouching

were carried out. The conservation

was done using Maimeri® restoration



colours which perfectly matched the

cleaning and reconstruction of both

varnish gloss level without adding

wood and polychromy. The burned

any extra medium. The tratteggio

and missing wood was reconstructed


using lime wood strips. It was necessary

blending of the reconstructed areas

to apply a filling to the reconstructed

with the surrounding original, leaving

wood surfaces to match the height

them minimally recognizable at the

and texture of the surrounding area.

same time (Fig. 1).


Lana Kekez | Kristina Krivec | Julija Baćak



Figure 3 • Archival photo, October 1987 and the polychromy reconstruction based on the archival photo

Figure 4 • The ‘Virgin Mary and Child’ painting after the treatment

Retouching relegious paintings – examples from private practice


and also help dating the damage to

to add a dammar varnish solution to

During the cleaning process it was

somewhere in the last thirty years

the retouching colours. To match the

possible to remove only some of the

(Fig. 3).

texture of the original paint layer and

fillings and overpaints (Fig. 5). Since

After the stabilization of the support

to blend the reconstructed areas with

those were firmly attached to the

and the polychromy, and the cleaning

the surrounding original, pointillism

underlying layer and weren’t covering

of the surface, the painting was lined

retouching was applied in the flesh

large surfaces it was decided to keep

with a dimensionally stable synthetic

tones (Fig. 3) and the background.

them. Extensive damage and losses

canvas using Beva 371. The losses in

The draperies were retouched using

had to be reduced throughout the

the ground layer were reconstructed

a combination of tratteggio and

retouching process (Fig. 5).

using Plextol® B500 and Tylose®

pointillism (Fig. 4). To protect the

The painting was lined using Beva

MH300 based filling.

painting from humidity within the

371. Losses in the ground layer were

The retouching was based on the

stone niche, a new wooden box with

reconstructed using rabbit glue and

archival photos and on the stylistic

a protective backing was introduced.

Bologna and Champagne chalk, toned

characteristics of the painting. The obvious similarity in the shape of

to match the colour of the original layer. An


the Virgin’s and the Child’s faces was

Figure 5 • Detail of ‘The Dead Christ’ during the cleaning and after the treatment


Lana Kekez | Kristina Krivec | Julija Baćak



gouache-tempera layer was used

very helpful in the reconstruction

The 18th century oil on canvas

only to define the main forms and

of the Virgin’s nose, both in form

representing the Dead Christ comes

shadows, thus leaving the possibility

and in colour (Fig. 3). An underpaint

from the Saint Nicholas church

of imitating the overcleaned paint

Maimeri® gouache-tempera


in Šibenik. The painting was found

layer during retouching. The painting

was used only to define the main forms

in a poor state of preservation,

was varnished with 20% dammar

and shadows. Varnish tests showed

showing many deformations and

in double rectified turpentine with

that dammar will give a satisfactory

losses in both the canvas and the

the addition of 2% Tinuvin 292. The

level of saturation and intensification

polychromy, most of which caused

final retouching was done using

of the original polychromy, especially

by poor microclimate conditions

Maimeri® restoration colours. The

in the darker areas. The painting

and handling. The polychromy was

addition of a dammar solution for

was varnished with 20% dammar in



increased gloss was necessary in

double rectified turpentine with the

aggressive cleaning, with the red

all parts of the polychromy. The

addition of 2% Tinuvin 292. Maimeri®

ground layer being clearly visible

retouching was done with various

restoration colours, used for the final

through it, especially in the dark

graphic forms (dots, dashes, lines,

retouching, perfectly matched the

background area. In many areas

spots) and applied irregularly to

varnish gloss level without adding any

the paint was covered with fillings

match the badly damaged and

extra medium. The only exception

and overpaints, with a thick layer of


was the dark zone of the Virgin’s

darkened and yellowed varnish and

toned ground layer slightly visible

blue mantle where it was necessary

surface dirt on top (Fig. 5 and Fig. 6).

where necessary (Fig. 5 and Fig. 6).




polychromy, leaving


Figure 6 • ‘The Dead Christ’ before and after the treatment

Retouching relegious paintings – examples from private practice


Paraloid™ B72, than to that of the


dammar, a natural low molecular When dealing with paintings from church interiors it is necessary to

weight resin from the same group of terpenoid resins as mastic.

take into consideration that they are

To match the texture of the original

a subject of veneration. This usually

paint layer and to blend reconstructed

means a complete reconstruction

areas with the surrounding original,

of the missing parts is required


whenever it is possible. Old photos

The chosen technique (pointillism,

taken before the damage prove highly

tratteggio or combination of various

valuable in such cases. Decisions

graphic forms - dots, dashes, lines,

about reconstructions of the missing

spots) depended on the characteristics

polychromy, about the appropriate

of the original painting technique, as

methods, techniques and materials,

well as on the changes in the paint

should be made by a group of experts.

layer texture and appearance caused

In all three cases the mastic based

by ageing, degradation and previous








activated with butanol, were used for retouching and were applied on top of the isolating varnish layer. As expected, the colours were semiglossy to matt in appearance. In the first case, where Paraloid™ B72 was

the Conservation Department in Šibenik.

used, the gloss of the retouching

[1] All three conservation treatments were

colours matched that of the varnish,

funded by the Ministry of Culture of the

[2] Maimeri® Restoration Colours data, Talas,

Republic of Croatia, through its regular movable

Official website of Bookbinding, Archival &

cultural heritage conservation funding programs.

Conservation Supplier, Available at: http://www.

On behalf of the Ministry, the supervision of


the treatment was carried out by conservators

[12 March 2018]

excluding the need for additional medium. In the second and third case, where dammar was used as an isolating varnish, it was necessary to add some extra dammar solution to the retouching colours, especially in the darker areas. The gloss of the mastic based Maimeri® restoration colours empirically proved closer to that of the synthetic polymer resin



Lana Kekez | Kristina Krivec | Julija Baćak

in charge. In the case of Saint John the Baptist,

[3]The Photo Archive of the Split Conservation

the painting conservators were Ivan Alduk

Department of the Ministry of Culture, Inv. num.

and Katarina Cvitanić from the Conservation

84716, Neg. num. L-25935, taken: J. B. 10/87.

Department of the Ministry of Culture in





Imotski. For the two paintings from Šibenik, The

Maimeri, Official website, Available at: http://

Dead Christ and Virgin Mary and Child, the

www.maimer i.it/en/products/gouache/

conservator in charge was Diana Bolanča from

maimeri-gouache.html [12 March 2018]

Nome artigo


Keywords Wall Painting; Trecento; Barcelona;


a geometrical and easily repeatable

Colour reintegration;


Calcium hydroxide nanoparticles;

2.The mimetic retouching system from the 1929 intervention, to which the


public that visits the chapel has become accustomed over the last century. The objectives of the pictorial retouching project have been the


following: This work is an account of pictorial retouching of large lacunae affecting geometric motifs and false marbles decoration that frame the scenes of the wall painting in the chapel of Saint Michael, 1346. [Fig.1].

This treatment replaces an earlier one, carried out in about 1929, made with semi-soluble vegetable and

Removal of the altered colour

retouching. •

Compatibility with the original

protein binders. It was decided to

painting (mixed fresco and secco

remove because it showed chromatic

technique, with presence of various

alteration and because it had been

binders such as oil and proteins).

Rosa Senserrich-Espuñes (1) | Lídia Font-Pagès (2) 1. Department of Arts and Conservation, Faculty of Fine Arts, Pau Gargallo 4, 08028 Barcelona (Spain), rosa.senserrich@gmail.com 2. Conservation Service, Barcelona History Museu, Llibreteria 7, 08002 Barcelona (Spain),


Figure 1 • Deployed image of the mural paintings of the chapel, currently under restoration.

The mural paintings in the chapel of Saint Michael are a unique example of artistic quality in Catalonia that combines local tradition with painting techniques of Toscana 1300


. They


. Nanolime dispersion was


applied on a plaster reintegration that

Durability by selecting stable materials

needed to be removed as well, since

that do not undergo chromatic changes.

second phase of retouching of the extensive

it contained soluble salts that could

This means avoiding organic binders

carried out in the past can be observed.

areas derived from the substitution of the

damage the original lime mortars.

that may be altered in conditions of high

A key aim of the conservation project was the removal of the altered colour retouching made

incompatible mortars [5].

with vegetable gum and other semi-soluble binders

applied in earlier interventions on

This system offers a greater duration

gypsum mortars that fill the gaps, such as the restoration carried out by Arturo Cividini near

of retouching: high resistance to the


alterability caused by light, no yellowing

have survived in a good state of preservation in a small cell attached to the cloister. However,

used to fix the high-quality pigments in the

some alterations due to ageing of the materials and the consequences of different treatments



or the recent one conducted by Diputació de Barcelona around 1951.

Two important factors have been

humidity or favour the development of

taken into account in choosing the

microorganisms. This aspect is relevant

type of retouching:

because the paintings present some

1. The fact of certainly knowing

mottling caused by an ancient fungal

what the missing decorative motifs

attack and sensitive areas painted with

of microorganisms in the event of any

are. It was not necessary to resort

organic binders, although they are highly

adverse environmental conditions.

to the hypothesis since there was


The restoration group coordinator has considered the nature of the materials to be used, valuing


their full compatibility with the original technique, maximum durability and sustainability.

becoming a focus for the development

The reintegration of large areas decorated with geometric motifs, using discernibility criteria, combining fresco and secco techniques, has led to an innovative use of calcium hydroxide







1. Application of a lime and sand intonaco. Figure 2 a,b • Fresco process

Legibility for easy recognition,

In addition, retouching with pigments

combining a mimetic retouching

and a nanolime dispersion provides

system with a final treatment that

more time for intervention and does

allows to distinguish the original parts

not interfere with the preceding

of the reintegrated ones.

pictorial strata made in fresco.

Re-treatability to guarantee that it

can be retouched with a compatible

Retouching method of large lacunae

secco technique in the future.

in cosmatesque friezes

Sustainability for the restorer in

The followed retouching method is

charge of the intervention and for the

based on two stages: the first one is


carried out with a fresco technique on

a lime mortar developed specifically 2. MATERIALS AND METHODS

for this procedure. The second one is carried out with a secco

The proposal is a retouching in

technique, using a calcium hydroxide

fresco with a final treatment in

nanoparticles dispersion as a binder.

secco using a nanolime dispersion

At the end, the two phases should

(Nanorestore ® in isopropanol, code

show a strong cohesion due to their


full compatibility. [ Fig.2 a,b-3].


at a 1g/l concentration.

This dispersion is mixed with lime

FRESCO PROCESS (for backgrounds):

compatible pigments, and the final

of reintegrated areas and provide system. These vertical lines are



lime-based create


chromatic base of the frieze.

applied to the missing false marbles of





chromatism according to the zone.

3.  Stencil with ochre pigment to distinguish it from the original

2.1 Analytical test to evaluate

black carbon stencil.

nanolime behaviour

4.  Application of the background

A reintegrated area with the

colours with diluted compatible

retouching system presented has

pigments in water (ochre, iron

been analysed [7].

oxides, vine black and white lime) SECCO PROCESS (for intermediate and final touches):

The used techniques were Optical Microscopy



Stereomicroscope and Nikon Eclipse

5.  Application of a grey cerulean





blue tone, mixing the pigments



light SR-µXRD, line XALOC BL13 (ALBA




nanoparticles dispersion.



synchrotron, Cerdanyola del Vallès). In

6. Drawing of multiple vertical blue lines.

this case, the measures were taken by

7. Drawing of multiple vertical raw


umber lines, to tint brightness of

The results confirm that a continuity

previously applied inks, integrating

of calcite is observed throughout the

new areas with the original ones.

depth of the sample, with a higher proportion of calcium carbonate




dispensed with, choosing a retouching

flat colour inks, harmonizing the result

Rosa Senserrich-Espuñes | Lídia Font-Pagès



combined with the previously applied


2.  Application



original painting.

followed in the friezes has been

nanolime reintegration) [Fig.4 a,b].

which facilitate a rapid recognition

with weathering and alteration of the


second retouching layers (fresco and

a distance of approximately 2mm,



observed between the first and

of several vertical lines, separated by



in the mortar. No discontinuity is

adjustments are applied by means



Figure 3 • Secco process

based on the carbonation of calcium hydroxide.

The use of lime and

Figure 4 a,b • X-ray diffraction: 3D distribution profile of crystalline compounds of a sample cross section (a). Micro sample of a retouched area: Lime mortar/Green earth, background/Raw umber, vertical lines (b).

nanolime offers a result that fulfils the initial established objectives. As regards the fresco retouching, durability is guaranteed. As regards the retouching in secco, nanolime has an appropriate behaviour as a binder for mineral and compatible pigments, mixing well in the palette and facilitating the drawing of lines. If any rectification is needed, lines can be erased using a moistened cotton swap with distilled water before the carbonation process starts. The




nanolime and the retouching in fresco is good and, after a year, no detachment between layers has been observed, thus ensuring the long-term durability of this chromatic reintegration. This method of retouching is related to medieval painting in mixed technique, giving a predominantly matte appearance.

4. CONCLUSIONS The retouching made with fresco technique presents an important challenge. It requires a considerable skill





and confident assurance in colour application.





maximum guarantees of durability, reducing





intervention in medium term. Retouching with nanolime on reintegrated areas in fresco allows adjusting and tinting the base inks, also based on the carbonation process. Retouching without organic binders is especially interesting in places with a high RH such as Barcelona, an area with a Mediterranean coastal climate where high levels of humidity can be reached. This system reduces the risk of microorganism proliferation [Fig.5,6].

Calcium hydroxide nanoparticles for wall painting retouching. The chapel of saint michael in the royal monastery of pedralbes, barcelona


4.1. Acknowledgments:



Eiden, conservator-

restorer of mural painting who has put into practice its expertise on the fresco technique and has made this reintegration system possible. To Anna Castellano,director of the“Reial Monestir of Santa Maria de Pedralbes” for believing in this intervention.

Figure 5 • Central wall with pictorial reintegration completed. © Photo Josep Casanova Figure 6 • UV light: the darker areas in the wainscot and friezes correspond to the surfaces reintegrated with the proposed method. © Photo Josep Casanova



Michael’s chapel in the Monastery of St Mary

stauro delle pitture murali della capella di

of Pedralbes. In FONT, Lídia, ed. – Conserving

Sant Miquel, Monastero de Pedralbes di Bar-

Trecento mural paintings. The role of painting

cellona. In PFEIL Mathias, ed. – Retrospektive

technique. Barcelona: MUHBA Documents,

& Perspektive. Methoden und Techniken in der

Ajuntament de Barcelona, 2015, pp. 70–83.

Wandmalereirestaurierung. (Schriftenreihe des

[2] ARTE-LAB SL – Estudio de los materiales

Bayerischen Landesamtes für Denkmalpflege,

orgánicos presentes en diez muestras tomadas de

Nr. 17). Werkstattgespräch 9. und 10. Mai

los murales del Castillo de Pedralbes. Unpublished

2016. München: Volk Verlag, 2017, pp. 202-216.

report, Madrid: Arte-LAB, SL, 2012, pp. 12–13. [3] TRENS I RIBAS, Manuel – Ferrer Bassa i les pintures de Pedralbes. Barcelona: Institut d’Estudis Catalans, 1936, pp. 29–30.


Rosa Senserrich-Espuñes | Lídia Font-Pagès


The conservation of the paintings in Saint

[6] CTS Srl. Official website, Nanorestore® Technical Data Sheet. Available at: http://www.ctseurope.com/en/schedaprodotto.php?id=232 [28.01.2017]

[4] BAGLIONI, Piero (et al.) – Consolidation

[7] SALVADÓ, Nati; BUTÍ, Salvador – Infor-

of Wall Painting and Stone. In BAGLIONI,

me 2017 (II). Pintures Murals de la capella de

Piero; CHELAZZI, David; GIORGI, Rodorico

Sant Miquel del Monestir de Pedralbes. Unpu-

ed. – Nanotechnologies in the Conservation of

blished report, Vilanova i la Geltrú: Depart-

Cultural Heritage. A compendium of materials

ment of Chemical Engineering. Polytechnic

and techniques. Dordrecht: Springer Science

University of Catalonia - Barcelona TECH,

+ Business Media, (2015), pp.15–59, doi:

2017, pp. 22-–27.

Calcium hydroxide nanoparticles for wall painting retouching. The chapel of saint michael in the royal monastery of pedralbes, barcelona


Keywords Double-sided processional flag-icon, compression of paint, Resin retouching,


Paraloid B-72®, the Theophany. The object depicts

Aerosil 200®.

on its verso a double portrait of two juxtaposed patron saints related to the autumnal time of the harvest: the full figure portrait of Saint Martyr Tryphon of Campsada, Syria, accompanied by


the Venerable Saint Petka (Paraskevi)

Filip Adrian Petcu

1.1 The flag-icon and its ritualic

critical conditions of their current

from Epivato(Paraskeva of the Balkans).


use and storage. Processional flags

On the front side of the flag we find



the representation of the festal icon of

various annual religious processions,

the Theophany, a typical composition

but also occasionally during military

with four figures in the presence of

events, riots, revolutions and wars,

the descending dove as symbol of

as symbolic effigies of an emerging

the Holy Spirit. The depicted scene

national consciousness in Europe and

refers to the Baptism of Jesus Christ

the Balkans starting with the mid of

in the Jordan River, event celebrated

the 19th century.

in the Orthodox Church on the 6th

Timisoara Museum of Art; Piata România; E-mail address: fillip.arte@gmail.com , , Unirii nr. 1, 300085 Timisoara, ,

Double sided painted processional flags from the mid of the 19th century are quite a few well preserved in Romania. If we still find such artefacts in local churches, most of them are in an alarming state of preservation, due to specific reasons regarding the





of January (Gregorian Calendar) or

processional flag is one of the rare

the 13th of January (Julian Calendar).


kind, carrying

This feast includes the blessing of the

even more an authorial inscription,

waters and rivers in the name of the

commemorating three iconographers

Holy Trinity by the participating clergy

-George, Kostandin and Kostandin

and the local community engaged in




The paper discusses the particularities of a retouching case on a rare object, a 19-th

study tests over retouching options,

century double-sided flag used in religious processions of the Orthodox Church as

observed in optical microscopy, using

part of a distinctive ritual within a rural agrarian community of Southern Romania.

several synthetic resins in solutions,

Along with surface deposits and evidence of aged paint, the major issues of aesthetic


concern appear to be random traces of dripping paint occurring from architectural

Aquazol® 200, Aquazol® 500, Laropal®

renovations and more particular, areas with mechanical compression caused by

A-81 and an acrylic dispersion (EA/

(Zugravi). The painters are mentioned

a large procession which accompanies

past inadequate attempts of scraping that paint material from the original pictorial

MMA, CTS® ACRIL® 33), one choice

together with the inscription of the


surface. A high glossy surface, multidirectional polishing marks, and a disturbing

seemed to match the requirements.

contrast of texture interference on original material in paint show as consequences


year 1848, which points presumably

restoration of the cosmos through the

of the damage drawing a pole of discussion around the conservation approach of the


to the date of commission. The

redemptive mission of the incarnation

icon, its visual compensation, focusing on the methodology and materials needed to

selected as the optimal medium for

inscribed text is recorded on the

of Jesus Christ the Divine Logos. In

perform a satisfactory chromatic and morphological reintegration of this artwork.

retouching the degraded areas and

front side, along with the text of the

this context the carried flag is invested

Considering the irreversible mechanical compression of paint material and its

creating an appropriate, satisfactory

troparion of the depicted festal icon,

with a symbolical significance which

undesirable effect on the compositional syntax of the religious image carried during

integrated texture, that was similar in

with black characters on a yellow

points to the seasonal cycles in an

the outdoor processions, relevant details from the two compositions needed to be

its material consistency and structural

background, marking a painted frame

agrarian society, the rebirth of the

visually restored in order not to affect the ritual function of the icon. After preliminary

appearance to the original surface.

which encloses the composition of

creation, the blessing and working of


B-72 silica,













the land and the annual harvest of the

expected from such cultic objects used

and particular for the country’s


and only later, starting

in churches, which are meant to be

record presently to be the common

crops, as an anthropological reference

both indoor and outdoor, they were

identity and culture. The large fund

the 70s, it began to adopt tendencies

restored to “their original beauty”.

acceptable options for retouching

to the human passage on earth, in

constantly subjected to mechanical

of painted artefacts from the current

of the school of Rome . Up to this

These make the two irreconcilable

icons in Romania. Polysaccharides and

perspective of the promised harvest

movement, tensile stress and thermal

public collections and state museums

day the local trends in conservation

poles around the debate.

lipids, or denaturated proteins are the

of the afterlife.

expansion during their translation in

in Romania are mainly icons, mostly

tend to suggest almost exclusively

Traditionally, icons are painted with

ingredients of the two historical media

Considering its thematic substance,

processions, when such flags were

late- and post-Byzantine icons, initially

the use of classical natural materials in

natural materials, as they symbolize

that were used by artists and are still

this painted flag used to be also

frequently exposed to critical variations

property of the Orthodox Church in

the treatment of icons, particularly for

in their process the sanctification of

acceptable for retouching, if used

carried in religious processions during

of the environmental parameters. The

Romanian. In the course of the 20th

the consolidation of paint layers and

matter through the synergic work

properly.[5] There are also occasionally

the blessing of the agricultural fields,

object indicates, on both of its sides,

century a considerable number of

retouching operations. [3]

of the human iconographer and the

rare cases when commercially available

when lands were sprinkled with holy

visible structural damage of the textile

icons originating from remote churches

Relying during the past decades

consenting blessing of God. There is

oil colours are drained on blotting

water, not only at the moment of the

support, along with other specific

became part of newly founded local

on the Charter of Venice and the

a theological argument supporting

paper from their excess of oil binder,

very feast of the Theophany, but also

marks of material degradation through

public collections, county museums and

theory of Cesare Brandi, some of the

the use of natural materials in the

being sometimes blended with resinous

during several other special days of the

mechanical stress, with a considerable

national museums. The artefacts were

restorers and art historians started

conservation of icons, making them

varnish (damar or mastix) for inpainting

year, as are, in spring, the first Friday

impact on the pictorial surface and the

selected from various monasteries

to appreciate the concept of the



over older wax fillings. In rare situations

after the feast of the Resurrection of

physical appearance of the depicted

and churches by professionals who

minimum intervention, stating that less


; however, natural materials

some restorers use modern mastix

Christ and in autumn, the feast of the

images, both on front and rear, altering

carried field campaigns, purposing

aesthetic intervention on icons would

have their limitations due to their

retouching colours from the Maimeri

Exaltation of the Holy Cross, as well

the morphology of the painting.

to identify valuable objects, to be

be rather more preferable for the sake

inherent properties. Natural materials

Restauro® line to inpaint icons.

The conservation issue of the flag

saved, conserved and further meant

of preserving authenticity of icons.

are generally preferred in conservation

In terms of methods of inpainting

became therefore a challenge, not only

for public display. Many of these

This attitude proved to be obviously

treatments in Romania, as opposed to

in Romania, differentiated retouching

1.2 The object. Origin and

from a technical and methodological

artefacts were collected in central

in contradiction to the official point of

many synthetic polymers which are

by optical division is preferred against


perspective, but also from a conceptual

storages, where proper preservation

view of the Church which highlights

avoided apriorically by most of the local

the standard or mimetic type of

The object of our reference was

point of view, considering its cultural

measures were not always met, a

the importance of the cultic function

conservators. The apparent reason for

retouching. Variations of the Roman

initially preserved in a wooden church

identity, as well as its actual purpose.The

reason for which the conservation of

of the icon, supporting rather more an

a sceptic attitude in Romania, towards

vertical linear crosshatching, trattegio/

in Țara Românească, the county of

processional icon on a textile support is

these artefacts became an issue with

aestheticizing restoration of a formal

the uprising world of synthetic materials

rigattino, sometimes combined with

Gorj, the commune of Bărbătești, the

a cultic object in the first place and the

time. The number of professionals in

integrity, as much as possibly agreed,

in conservation, was taught to be

thin velatura/glazing or alternated

village Socu, where it suffered several

liturgical function of the icon within the

museums was far too outnumbered

in respect of the depicted subject

rejected with the implacable argument


degradations due to various specific

Christian Orthodox ritual remains to be

to cover the needs for the amount of

of the image. The icons of the saints

of the unpredictable ageing of these

are generally applied, in lighter, cooler

functional contexts occurring in such

considered as essentially in formulating

objects which needed treatment and

are part of the church ritual already

new materials, the compatibility issues

undertones of colour, for the visual

wooden churches. A few decades ago

a concept over the conservation

only few restorers could benefit from a

for two millenia.

There is always

and their questionable reversibility.

compensation of either micro losses

the flag was saved by a local, belonging

treatment and the final presentation of

professional mobility abroad, at a time

a persistent debate between two

Considering this approach, the process

or larger lacunae.The inpainting occurs

to the community of the village, prior

the restored object.

when Romania was segregated behind

possible arguments of choice on how

of inpainting records, on national level,

mostly on flat, unstructured white

the Iron Curtain, up to December

to restore icons: the archeological

either the use of plain commercial

infillings, leveled at the even surface of

as during occasional times of drought.

to the demolition of that church,









when the object also became part

1.3 Icons and restoration in Romania

1989. The conservation methodology

presentation, advocated by museum

watercolours, tempera with egg yolk and

the surrounding original paint or slightly

his private collection, preserving the

The process of restoring religious

for icons employed in Romania

professionals, and the aestheticizing

dry pigments, or watercolours blended

below it, favouring generally a standard

memory of its context and history. As

icons in Romania is very representative

followed mainly the Russian school of

“reasonable” inpainting of icons kept

with a lean egg yolk emulsion. These

recipe for the putty. The putty is based

Filip Adrian Petcu

Retouching a doble sided 19th century processional flag-icon


essentially on proteic glue solutions

tempera can become brittle with

Regalrez® 1094 and PeOX Aquazol® 

to its original suspension system over

of the composition. The texture

the consolidation of the endangered

with micronized calcium carbonate

time and can delaminate easily if the

(in different molecular weights, 200,

a hand carved wooden spindle. This

of the painted surfaces had a waxy

areas of impasto paint, the surface

or calcium sulphate in suspension. In

emulsion is not properly adjusted

500), on synthetic thermoplastic fills,

element supported the upper edge

tactile feel, which might suggest the

cleaning of the painting on both of its

some cases of retouching paintings on

within the layering system. In this regard

considering the different properties

of the canvas to hang from above

possibility of use of a waxy medium

sides and the aesthetic compensation

walls of wooden churches, distemper

we agree that synthetic resins can offer

of these materials, their corresponding

on a taller handle, presently lost. The

as a protective coating. The main

on the damage.The main issue consisted

paint is applied in thin washes directly

superior solutions to build up proper

class of stability, their versatility, role

horizontal wooden element carries

issues concerning the legibility of the

in the reduction of the aesthetic

on the bare wooden support, by

textures of the inpainted areas, flexible

and advantages as useful, employable

a central drilled hole, as a fixing

images on recto and verso, consist


means of low concentration of proteic

structured films, with accurate tone

binders in the inpainting process.[7]

point addressed to the insertion

in areas with residues of dripped

between the irreversibly compressed,

glue suspensions and dry pigments,

adjustments, aesthetically matching

We tried to use these materials in

of the vertical handle used during

light blue paint, which were spread

burnished damaged original paint

in addition to a bactericide, antifungal

the original paint.

The later options

differentiated inpainting techniques

processions. On its upper edge the

irregularly over the surface and more

and the pristine surface with fabric


are always easily discernable by means

as well as in standard retouching,

canvas is tied by means of a helix-sewn

particularly, marks from a former

texture. The paint was tested for

Although egg tempera can give the

of non-invasive optical investigation.

considering the importance of the

hemp rope to the auxiliary horizontal

intervention which attests an invasive

water and organic solvents sensitivity

possibility to emulate various textures,

Tested synthetic resins, as recorded

visual appearance of the texture of

element, a spindle carved in hard

scraping of these dripping spots

and proved to be quite hydrophobic.

refering all these aforementioned

by recent professional literature, can

the fillings, as also the structure of the

wood. The textile rope became with

with a rigid tool and considerable

Following the criteria of a necessary

practices of retouching icons in

provide a base for properly structured

inpainting colour supposed to match

time oxidised and loose and imparted

mechanical pressure.The effect of this

permanent flexibility for the support,

Romania, there is apparently no

fills, providing a stable film for the

the original paint.[8] These later aspects

an unappropriate tensile force to the

attempt to remove the stains effected

the consolidation of the paint layer was

concern over the integrated texturing

retouching colour. They can be adjusted

are key elements to define a final

painted canvas. The textile canvas

irreversible consequences on the

performed with a diluted BEVA® 371b

of the matter which builds the

to the appropriate hue and tone, while

impact on the visual presentation of

is made from two sewn pieces of

paint layer and support, compressing

solution in Thinner 372®, followed by

support for the retouching, nor over

matching in gloss and transparency the

the restored artwork, its perception

linen fabric. It is unprimed and shows

the paint and transforming the

local ironing and drying under pressure.

the texture of the retouching itself.

exact, specific expectations for the

and legibility, paying proper tribute to

a prominent texture of its weaving

original texture of the canvas weaving


The tendency is rather a conceptual

chromatic completion.

the function of the image as a cultic

carrying mainly a thin to medium-

into a polished, glossy burnished

successfully employed in the cleaning

object, whereas not neglecting Brandi’s

thick paint layer with rare accents of

surface with diagonal polishing marks,

process, which meant basically reducing

emphasis on highlighting, by means








of the inpainted areas, a different,



paradigm, which defines the work of

impasto. Some areas of such impasto,

particularly discernable in raking

of the thickness of the darkened

discernable texture of the restored

Timisoara, Faculty of Arts and Design,

art by means of its polar, historical and

particularly on carnations, have been

light. The burnished areas carry the

surface coating, excessively oxidized

parts, distinguishable by the optical

Conservation Department, we were

aesthetical instance and significance.

lost probably during movements of

imprint of the metallic instrument

in some of the compositional areas.

division retouching method of the flat

the first professionals in Romania to

the textile support in conjunction

used in the previous cleaning attempt

Mixtures of naphta solvent, acetone

putty. In our opinion this approach

test and employ modern retouching

with the embrittlement of the aged

and require an adequate aesthetic

and isopropanol, both in liquid and

can lead to a difficult legibility of

media on icons, based on PVOH like

proteic and lipidic original medium,



gelled form were used in conjunction

the image and to an unsatisfactory

Mowiol® 4-88, PVAC(since 2006)

which flaked off.

retouching and textural integration

with aqueous gels of buffered 1-2%

contrast between different textures,



Except for some minor losses on

appearance indicates the overall


triammonium citrate solutions, in a

the flatness of new fillings with their

Flashe®(since 2006) and resinous

the perimeter of the textile support

presence of a dark brownish oxidised

medium and a dedicated technique.

corresponding inpainting and the

mediums based on HMWR and

of our flag-icon, the canvas showed

skin of medium covering the pictorial

micro relief of the original paint film.




surface, together with embedded

oligomers, as are Paraloid® B-72

planar distortions, consistent warping,

carbon particles and dust, visibly

Our treatment had to consider the

the surface with deionised water and


small tears and massive buckling due

impacting the overall perception

structural conservation of the canvas,

aliphatics. Using the same initial principle,

Watercolour alone cannot support building of structured films, while egg





Filip Adrian Petcu




synthetic 2008),




and A-81,

2. MATERIALS AND METHODS 2.1 The condition of the object


The surface`s





range of pH from 5.5 to 8.3, embedded in a Lubrizol Permulen® TR2 gel. The

2.2 Methodological explorations

residues were rinsed carefully from

Retouching a doble sided 19th century processional flag-icon


the canvas was reanchored on its upper

the better choice for a structured

be employable in an transparent or

as in a 1:10 V/V dilution with deionized

edge to the original spindle-shaped

inpainting medium, one tailored to

an opaque form, it should dry quite

water. As

horizontal wooden element, adjusting

match an appropriate textured surface

fast and stable without excessive

considered: 20% w/w acrylic solutions

an acceptable tension by means of

during further retouching The tests

swelling of the underlayers, it should

of either, Paraloid® B-72 (RI 1.47-1.48),

inserting a similar new hemp rope,

were observed under the microscope

be lightfast and photo-chemically

a short chain acrylic ester and Paraloid®

which replaced the damaged previous

with different magnification, to select

stable, it should preserve its flexibility

B-67(RI 1.48); a butyl metacrylate

one. The rope was infused with

an optimum binding material for the

features, cohesive and tensile strength,

polymer,[10] in Butyl acetate; a 20% w/w

Paraloid® B-72 for its hygrophobisation

inpainting of the aforementioned areas.

even in potentially oscillating slightly

urea-aldehyde resin, Laropal® A-81


damp environmental conditions and

(RI 1.50) in Isopropanol; 40 % w/w

threads. There was no need to use any

visual compensation of the texture

it should remain easily removable

solutions of PeOX , Aquazol® 200 and

putty to infill the losses, simply because

difference issue were considered on

on long term; it should conform in

500 (RI 1.52), both in pure form, as

a good tailored inpainting medium

matters of stability of the resins, as well

texture and structural appearance to

well as a mixture of both, in a 1:1 ratio,

could replicate closely the needed

as on the evaluation of physical and

the imprint of the original transfer

dissolved in an 96% Ethanol hydro-

texture, achieving a good compensation

optical properties like rheology of the

tool, preserving crisp, sharp details of

alcoholic solution. Finally, an additionally

of the compressed, burnished areas of

medium, flexibility of the film, drying

the application tool; the retouched

modified stock of Paraloid® B-72 20%

damaged paint.

time, workability, removability, opacity,

areas should not be affected by the

w/w solution was improved with the

transparency and gloss matching.

solvent of the final varnish and should

addition of an inert, stable material,

evaporation rate. Fumed silica is known

PM (BP 120 C ̊ ). Butyl Acetate (BP

remain permanently retreatable.

0.6 g hydrophilic fumed colloidal silica,

to “distribute any stress or strain during

126.1 C ̊ ), Isopropanol (BP 82.3 C ̊ ) and

Evonik Aerosil® 200, blended with a

the solvent evaporation and setting” of

Ethanol(BP 78,1 C ̊ ) were chosen for

Cappucino mixer into 12 g of 20% w/w

the B-72 medium

, imparting body

their low moderate swelling action on

B-72 solution. Hereby were improved

to the medium. The prolonging of the

oil films, considering a decreased risk

and the stabilisation of the textile

Paraloid® B-72, a class A stability polymer, additionaly stabilized with





We established some requirements would




Figure 1 • A  ll media texture samples on glass lamellae to be studied under magnification

a Hindered Amine Light Stabilizer,


Tinuvin® 292, represented our choice


for the isolating varnish, applied in a thin

medium in case of our flag-icon: the

coating dissolved in Ethyl Acetate(BP

medium should easily adhere to the

Different materials with various glass

the rheological properties of the

workability of the gel was adjusted

of swelling in the presence of B-72

77.1 C ̊ ). The separating varnish was

original surface without damaging it, it

transition temperatures were selected

medium and adjusted the gloss of the

with a minimal addition of Propylene

varnish as a separating, isolating layer.

meant to protect both sides of the

should have good thixotropic qualities

to be tested in various concentrations,

binder, while managing also the solvent’s

glycol monomethyl ether, Dowanol®

The corresponding boiling points of

painted canvas before the retouching

and a medium gloss when used in a

as resulting from Table 2. An acrylic

process. Several tests, as resulting from

very viscous form, as also a minimum

dispersion of EA/MMA, CTS® ACRIL®

Table 1, were performed to establish

shifting of tone after drying, it should

33 was tested in its pure form, as well








Table 2 • Index of the tests. resins & their solvents


these organic solvents allowed us to appreciate an acceptable grade of workability of the mediums during their application.

Table 1 • Ratios of resin:solvent:additive (v/v; w/w)

All the mediums were tested individually, both in their pure form, as also blended with dry pigments, PR 10 and PR 194, from Kremer Pigmente. These were applied with brushes and spatulas on glass lamellae, as in Figure 1, being further subjected to optical examination


Filip Adrian Petcu

Retouching a doble sided 19th century processional flag-icon


under the microscope. The samples

in gloss and to achieve a slight mattness

potential processions with the flag,

retouching. The standard Paraloid®

were observed using a Carl Zeiss Axio

of paint, without any additives. In the

even though there are records which

B-72 medium, based on the acrylic

Imager A1m microscope, using RL and

present case Laropal® A-81 medium

point to a certain stabilization of the

HMWR copolymer(MA/EMA) in Butyl

3200 K and the BF Mode, with four

has a far too glossy texture when

resin due to the presence of unbound


different lenses:

Epiplan 10x/20 HD,

used with the needed viscosity to

metal ions in pigments

. In respect

slightly higher gloss than particularly

Epiplan 20x/0.40 HD, A-Plan 20x/0.45

match the original colour’s structure.

to the acrylic dispersion, CTS ACRIL®

required for the present case and it did

and A-Plan 40x/0.65 and only the B-72

It definitely needs some developments

33, we appreciate that it has a far too

not conform to our criteria regarding

gel indicated to preserve the required

to modify some properties within the

low Tg, between 6-8 C ̊ , which can

structural mobility of the medium,

structure as defined in the earlier stated

stock medium. These include possibly

conduct for the medium to attract

textural workability and fidelity of


additives, like a matting agent, blending



imprint of the application tool. These

The aqueous dispersion of CTS®

of another resin a.o., either in order

Moreover, unmodified ACRIL® 33

desirable properties required more

ACRIL® 33 had a good adhesion

to decrease its refractive index or to

did not seem appropriate to create

than a basic retouching varnish, some

on the support in its pure form, but

balance the equilibrium between its

a sharp structured texture for a

particular improvements with special

not really in the diluted form. It did

gloss and consistency, while allowing

not conform in texture or gloss to

to better achieve a structured relief

the expectations of our retouching

of the paint at a lower level of gloss.

standard, neither did it preserve sharp

The three Aquazol® solutions, using

details of the brushwork. Paraloid®


B-67 (iBMA), having a Tg of 50 ̊C ,

of Aquazol®, 200, 500, were used

was excluded not due to its hardness

individually as well as in a 1:1 ratio

alone but also due to its crosslinking

of 200:500. Aquazols have similar Tg,

potential which would make it

between 69-71 C ̊ , obviously higher

decrease in solubility with time,

than some of the previous referenced

threatening a future removability.

resins, therefore we could expect


Figure 2 • B-72 inpainting gel under magnification


Filip Adrian Petcu





possibly an increased brittleness as

characterized as a resin with great

compared to the other materials, like

chemical stability and remarkable

B-72. A harder resin would not be

optical properties when compared to

suitable in any case in conjunction with

natural resins, it seemed here though

our quite mobile textile support of the

quite glossy for our requirements,

flag-icon. Beside these aspects we must

when applied according to the

record the hygroscopicity of Aquazol®

referenced viscous consistency. With a

which suggests the necessary addition

Tg of 49 C ̊ , higher than that of B-72,



A-81 solutions need very

to minimize its exposure to excess

low resin concentrations to decrease

moisture from the atmosphere during



, had a good adherence,

Figure 3 • The process of retouching and its results








Retouching a doble sided 19th century processional flag-icon


bulking materials, as already some

compensatory, as resulting also from

on B-72, now already about 70 years



Figure 2 and seemed quite compatible

old, offer great advantages and a vast

. Therefore, close to

to bridge between the areas of paint

multitude of improvement options

our formulated expectations was the

damaged by excessive burnishing during

through possibility of adjusting the

same Paraloid® B-72, dissolved in a

the past amateur cleaning attempts and

given properties with stable additive

20% w/w, resin to solvent ratio, in Butyl

the original textured painted surface

materials. These can help the design

Acetate, rheologically modified to a

of our flag-icon. Shrinkage of the paint

and the precise tailoring of more

form a gel, bulked with a thickener and

medium was not an issue at this time,

efficient systems. Nevertheless, theory

matting agent through the addition

neither during, nor after the solvent

alone and certain recipes cannot



evaporation, due to the reduced volumes

entirely cover every need in this

silica. This improvement created a

of gel paint necessary to build up the

complex field, where individual testing



structure of the retouching. Therefore,

and practice become crucial, as well as

medium, with better matching optical

evaluating potentially negative effects after

a continuously updated knowledge and

properties, an optimum drying time

solvent evaporation from the retouched

knowhow. Hereby only, we can hope

and a slightly reduced gloss. Colloidal

areas, no relevant changes in volume of

to manage and control parameters,

fumed silica has an open internal

the added paint became visible, nor did


structure which “is produced as

solvent evaporation negatively impact the

materials and the conjunctional role

a result of the formation process,

visual compensation through inpainting

of every particular ingredient which is

where silicon tetrachloride and other

of the damaged areas, particularly if we

employed in the retouching strategy.

volatile silanes are oxidized in a high

record that our retouching was built up

temperature flame aerosol process

layer by layer.

gels contain

available [14]




to produce small, essentially spherical primary particles which subsequently


collide to form rigid, covalently



of lead soaps in the degradation of an 18th

[3]UNGUREANU, Cosmin – Anatomia

century oil painting on a copper support. In

restaurării, București, Muzeul Național de Artă

LOPEZ, Laura Fuster, BLANCO, I. C.; MARTIN,

al României, 2016.

M. F. S.; Pascual, M. L. V. d. A; CARLYLE, L.;


Auli; Martiskainen, Petter; Nikkanen, Helena

2017, pp.145-152.

slightly different solvents and inserting

ed. – The Conservation of Late Icons, Uusi-


compensating a particular damage,

and a satisfying surface effect, which

retouching and have certainly also

an inadequate compression of paint

retained the impression of the brush

gained the trust of many restorers

caused by a failed cleaning attempt.

stroke while matching closely enough

over decades, there are still situations

As a result of the process visible in

the local relief of original paint, as

when the physical properties of such

Figure 3, the flag-icon was restored to

initially applied by the iconographer

media reach certain limitations and

a decent state of aesthetical condition,

on the canvas support.

can therefore be replaced by different

in respect of its material, historical and

media. Resin retouching media based

functional value.

Filip Adrian Petcu

murale, București, Meridiane, 1986.

guidelines of a gel recipe, by choosing



practical considerations on the presence




Paul – Conservarea și restaurarea picturilor

retouching method and following the

replicate an adequate textured relief


[8]PETCU, Filip Adrian – Theoretical and


method to fit our needs of visually


[2]MORA, Paolo; MORA, Laura; PHILIPPOT,

georgiană, Timișoara, Eurostampa, 2014.



pp. 607-634.

from a basic formulation of a resin



Republicii Socialiste România, 1976.

other metal plates). Production, degradation

structure of the gel allowed us to


Paintings, London, New York, Routledge, 2012,

relicvariu. Structură tipologică în arta eclezială

manage to implement a suitable


știință și artă, București, Muzeul de artǎ al

In our current situation, starting

media, like watercolour and tempera, consequently

Rebecca, ed. – The Conservation of Easel

WADUM, J., ed. –Paintings on copper (and

the appropriate additives, we could

The use of fumed silica within the

[1]ANASTASIU, Anastase, ed. – Restaurarea

[4]PETCU, Filip Adrian – Paradigma icoanei-


Although, traditionally

bonded aggregates”.[15]






Universitat Politècnica de València, Valencia, Leonardo;


Valamo The Valaamo Art Conservation

Paolo – Las resnas sinteticas usadas en el

Institute, 1998.

tratamiento de obras policromas, Padova: Il

[6]PETCU, Filip Adrian – Conservarea şi

Prato, 2005.

restaurarea unei icoane pe suport de pânză


cu tema Răstignirea Domnului şi însemnele

Robert G. Jr.; WHITTEN, Jill; MAYER, Lance;

Patimilior Mântuitorului Iisus Hristos, In Caiete


de artă şi Design, Nr. 3, Timişoara, Editura

SWICKLIK, Michael – Varnishing as part of

Eurostampa, 2016, pp. 59-66.

conservation treatment of easel paintings. In



Shawn; THOMAS,

STONER, Joyce Hill; RUSHMORE, Rebecca,


ed. – The conservation of easel paintings,

Stephen. – The imitative retouching of easel

London, New York, Routledge, 2012.



painting. In STONER, Joyce Hill; RUSHMORE,

[11]KOOB, Stephen P. –

Paraloid B72 as an adhesive: its application for archaeological ceramics and other materials, In Studies in Conservation, 31:1, 1986, pp. 7-14. [12]ARSANOGLU, Julie – Aquazol as Used in Conservation Practice. WAAC Newsletter, Volume 26, Number 1, January, [2004], pp. 1015. [13]BESTETTI, Roberto; SACCANI, Ilaria – Materials and methods for the self-production of retouching colours. Laropal A-81, Paraloid B72, Gum Arabic and Aquazol based colours. In RECH2: Proceedings, 2nd International Meeting on Retouching of Cultural Heritage, RECH 2, Porto, Portugal, 24-25 October, [2014], pp. 26-39. [14]KONECZNY, P. – An introduction to B72 Retouching gels. Properties of B72 Retouching Gels and their use. In ELLISON, Rebecca; SMITHEN, Patricia; TURNBULL, Rachel, ed. – Mixing and Matching: Approaches to Retouching Paintings, London, Archetype Publications, 2010, pp. 142–158. [15]BOLDRIDGE, David – Morphological Characterization of Fumed Silica Aggregates. In Aerosol Science and Technology, Taylor44:3, [2010], pp. 182-186.

The use of

Retouching a doble sided 19th century processional flag-icon


Keywords Polychrome wooden altar; Retouching; Gilding;


Conservation and restoration



2.1. Stratigraphic analysis of the


paint layer

Upon examination of the polychromy, The altar is made in polychrome, gilded and carved wood. The altar is

Sara A. Eterović


| Ivana Letilović


| Katarina Tomaš

composed of a predella decorated


with medallions, and fluted half columns with Corinthian capitals

TiaArte, obrt za restauraciju/ Conservation and Restoration Services/, saraanicic@gmail.com NeoRestaura, obrt za restauraciju /Conservation and Restoration Services/, letilovicivana@gmail.com (3) GoldArt, obrt za restauraciju/ Conservation and Restoration Services/, katarinatms@gmail.com. (1)

settled on predella. The entablature


rests on the columns and supports the




decorative vases. The antependium

it has been determined that under the visible paint layer there was a layer of gilt. A stratigraphic analysis was done in order to establish the number of coatings and if the original polychromy still existed.The samples were collected in different parts of the altar and were examineted and photographed under

of the paint layers, by which it was determined the existence of an overpaint over the original polychromy and gilt, the examination of the state of preservation of this layers was also carried out. The analysis was done on different parts of the altar in order to

a microscope (Fig.2, Fig.3 ).

establish the extent of preservation

2.2. Cleaning trials of the overpaint

the appropriate method and material

of the original paint layer and to find

is part of the altarpiece architecture, but it is stylistically different (Fig.1).

Figure 1 •  Altar of the Assumption of the Virgin Mary before conservation and restoration

and examination of the paint layers




to clean it.


ABSTRACT The altar of the Assumption of the Virgin Mary, dated from the 18th century, is

to the assumption that the whole altar

an example of the application of a different methods of retouching. The altar

was originally gilded.

is part of the church of Our Lady of Konacvine in Seget Donji, Croatia.

The wooden polychrome antependium

The aim of the final presentation of the altar was a different approach to the

with marble effects, added in the late

integration of the painted and gilded layers. After removing several coatings of

19th century, was finally presented

overpaint we found that the main retable was originally gilded. The retouching


approach was to fill the small lacunae with the rigattino method using tempera


and the big lacunae with gold leaves. A marbled paint dominates the entire

retouched with tratteggio using acrylic

altar surface, whereas the damaged areas show a gilded layer, which has led



original parts


polychromy. the


The were

Figure 2 • Micro-section of the paint layer taken from the antependium

Figure 3 • Micro-section of the paint layer taken from the entablature

humid stone floor, which required the

methods were necessary in this case

use of waterproof retouching colours.

due to a number of aspects that

Different retouching approaches were

conditioned the decision.

used due to the texture of the paint Figure 4 • Examination of the paint layers

Alongside with the examination,

Figure 6 • Antependium after retouching

2.3. Overpaint removal

order to match the new tone with the old one, newly gilded areas were toned

The overpaint was removed with an

were carried out. This tests were

industrial oil-based paint removing gel.

executed by using solvent gels and

The gel was applied on the surface and

solvents that work on an oil-based

left to rest for 15-20 minutes until the

overpaint. No water based solvents

oil-based layer softened. After which

were used due to the presence of a

it was removed with cotton balls. The

water gilding which was found in the

remains of the paint were eliminated

original paint layer (Fig.4). Tests using

with acetone. After the use of these

Pemulen Tr2 gels were performed in

solvents the surface was neutralised

order to soften or remove the top

with Shellsol T.

the retouched area is well visible from

2.4. Retouching methods

integrates with the original gilding

should have to be removed with a solvent that would not damage the original gilt. During the application of the gel it

Before retouching, the reconstruction of the wooden structure was carried

with varnish based colours (Maimeri Restauro Varnish Colours). Smaller damaged




with tempera colours with rigattino technique (Fig.5) and also using 23 K gold powder with 10% Paraloid B72 (solved in toluene) binder. This method was chosen because up close, and from a distance it nicely which, in turn, emphasises the visual harmony of the entire altar.


binder, on which the solvents work

A layer of bole poliment was applied

poorly. It was assumed to be casein.

on areas where golden leaves would

After repeated attempts, it was

later be placed. A red and yellow

possible to remove the overpaint.

bole was used, which was toned with

It was decided to maintain the

tempera in an attempt to reach a

recent layer of the antependium

tone close to that of the original. The

that has oil-based paint. In view of

poliment was polished and prepared

the fact that the original is also oil

for gilding. Gold leaves (23 K ducat

based, it was not possible to remove

doppel) were applied using a water

the overpaint without damaging the

gilding technique. This gold differed

original polychromy.

from the original in tone and gloss. In

Sara A. Eterović (1) | Ivana Letilović (2) | Katarina Tomaš (3)

In view of the stylistic differences between




the upper area of the altarpiece, it was decided to retouch the lower element in trattegio using acrylic colours


techniques and materials depended The use of different retouching Figure 7 • Altar of the Assumption of the Virgin Mary after conservation and restoration

on the degree of damage and on the position of each lacuna. The intended appearance of the altar after the restoration was a visual integration of the original gilt and the retouch from the viewer’s perspective, highlighting their difference at a closer look. The altar required re-gilding of the damaged areas and retouching of the original gilt, so we used a combination of two methods which, as a final result, proved to be an ideal solution. antependium,



completely different in style, was


based applied in combination with a

used on the altar. The decision on the



out and the surface was prepared.

was found that the overpaint was oil-

method, a special attention was paid to the variety of techniques and materials

rehearsals for removing the overpaint

paint layer, whereas the last layer


layer and the level of damage (Fig.7).

Figure 5 • Retouching using rigattino - detail from the pediment.

In the choice of the retouching



colours), while maintaining the visual integrity of the set. (Fig. 6) The level of damage of the antependium was considerable and was caused by a direct contact with a

retouched with acrylic colours. The acrylic colours were chosen because of their waterproof quality, and due to fact that the antependium was in direct contact with a humid church floor.





This altar was treated as two separate

Résumé: Les monuments de Seget. Vjesnik

units. At the same time, it had to

za arheologiju ihistoriju dalmatinsku, Split,

be taken into account that the altar should be presented as a whole and in connection with the other two altars in the church, belonging to the same period.

LVIŠLIX/1954Š1957, vol. 2, pp. 213Š232, pp. 219-220 Ivana




Restoration Interventions to the Altar of the Assumption of Virgin Mary”, restoration documentation, 2015.

Selecting methods for retouching a polychome and gilded altarpiece with elements dating from diferent periods


Keywords Retouching; Retouching survey;


Retouching materials. For reconstruction the conservator need to add materials such as fillers, binders, pigments and varnishes, among




process requires good lighting and permanent materials.


Conservators are often faced with

Ana Bailão (1,2) | Liliana Cardeira (1) 1. C  IEBA, Faculty of Fine Arts, University of Lisbon; Largo da Academia Nacional de Belas Artes nº 14, 1200-005, Lisboa; E-mail address: lilianacardeira@gmail.com 2. 2 . CITAR, Portuguese Catholic University, Centre Regional of Porto; Rua Diogo de Botelho 1327, 4169-005, Porto; E-mail address: ana.bailao@ gmail.com

It is understood that the term “reintegration” or “retouching” implies on one hand the restitution of parts dismembered in their original place and, on the other hand, the reconstruction of an element from its fragments with the replacement of deteriorated elements or the realization of additions, which provide stability and visual unity to the work being performed. So, the main objectives of reintegration or

retouching are, therefore, the formal,

making difficult decisions regarding

structural and aesthetic restitution of

appropriate retouching materials for

the cultural heritage [1].

mixing and matching. Ancient and

If in the first situation, that of restitution,

contemporary works of art have

there is a point of view associated with

different requirements. During the

the union of the original fragments, in

20th century, there was a vast increase

the second it is discussed in the sense

in the variety of materials that artists

of introducing new materials, in order

had access to. Organic and inorganic

to give the object structural and visual

materials were mixed. It is essential

uniformity. In both approaches, it is

that conservators select retouching

intended to act on the matter that

materials properly, having in mind the

constitutes the object.

hue, saturation, brightness, texture,

Fig. 1 • Image illustrating some of materials for retouching: aqueous binder’s solutions, solvent binder’s solutions and dry solutions. © Ana Bailão.

smoothness, thickness and refraction index, among other things. There is an innumerable amount of information about retouching materials already available for the conservator [2-5]. However, finding the ones with quality, technical, pros and cons information can require some

Abstract The aim of this article is to compile a list of materials that are acceptable for the retouching process. The list is not exhaustive but will help the conservator in the

time and research. The scope of this research is make a survey of the main characteristics and properties of some materials used in

decision-making about materials. The materials are divided by group´s: aqueous

the retouching process. For a question

binder solutions, solvent binder solutions, dry solutions and other solutions.

of methodology, the materials will

be divided in four groups: aqueous

They can be used in specific tasks.

similar to gouache and watercolours.

increased by applying multiple layers.


, soluble in almost all paint solvents as

in Laropal® A-81. Have similar

binder’s solutions, solvent binder’s

These markers are highly pigmented

Dries to a water-soluble film. It can also

In viability tests JunFunori® was

hydrocarbonate as shellsol or propan-

characteristics to Gamblin® version

solutions, dry solutions and other

and since they are water-based they

be used as the first layer on a support

resistant to biological attack

. Also,

2-ol. Alumina hydrate is added to paints

but the result of the retouching of

solutions [Fig. 1].

provided a permanent ink flow. This

to reduce absorbency, thus facilitating

when naturally aged it can yellow

with organic pigments to increase their

Kremer paints can be too glossy. In

characteristic is good for the pointillism

subsequent colour washes. Has the

slightly and brittle when dry. Is likewise

tint strength and also a white extender

both situations the solvents required

technique but did not allow blending

capacity of increasing fluidity of paints

very expensive and the recipe is 1g

made from calcium carbonate (PW18).

to dilute them make them unsuitable

or the creation of hues gradation when

like gouache and can be thinned to

for 100 ml water.

This extender is used to increase

for retouching acrylics and other

more than one layer is needed [7].

create subtle washes when used with

transparency, or translucency of the

solvent sensitive paint films.

1.1 Aqueous binder solutions

One of the commonly used materials in the retouching process is the

Other binder is Aquazol® which

watercolours.They comprise pigments

Gouache is another option material.

pigments. Used as a binder, more



colour without changing its viscosity.The

According with brand information

usually bound in Gum Arabic and

Comprises pigment bound in Gum

medium produces a watercolour and

comprising oxazole, 2-ethyl, 4,5 dihydro

paint generally dry to a matt finish. So,

Golden® MSA Conservation Paints

creates a transparent and luminous

Arabic and is distinguishable from

less medium produces colours with

homopolymer. Is sold in different

gloss can be increased by adding more


layer of paint/retouching.

watercolour as it has a higher pigment

matt and opaque appearance similar

molecular weights: Aquazol® 50, 200

resin. Some of the solvents used to

acrylic resins (n-butyl methacrylate

to gum ratio. It also contains extenders

to that of tempera or gouache.

and 500

. All these molecular weight

dissolve the colours are Ethyl L-lactate,


resins are soluble in acetone, water

Dowanol® PM, Shellsol® D40 and

retouching as the solvent causes


under layers. The paints remain

Watercolours are hard to colour match



dries, but

Another aqueous binder is the





as chalk. The colour match is a little

characteristic depends of the brand.

more difficult as watercolour because

JunFunori®, the


and ethanol. Aquazol has neutral pH

The brand Schmincke® watercolour,

they change the colour and they can

from Funori. Funori is a 100% natural

and is thermal stable up to 60 degrees.

especially Horadam, are one of

become whiter or darker during drying

dry seaweed polysaccharide, a “red

the glossiest when compared with

due to the extenders. Gouaches have

standard watercolour . [6]

A recent example of watercolour is the QoR® watercolour, designed




mineral mainly

spirit-based suitable



soluble in White spirit and the

A500 is best for recreating surfaces

Colours are excellent for creating

pigments are lightfast. MSA colours

algae” named Gloiopeltis Furcata. The

and binder for chalk fillings. The paints


retouchings. The

can be blended with oil and alkyd

normally more than two pigments

non-purified material has been used

have little colour change on drying and

pigments are lightfastness and the

paints. They are not suitable for

in the mixture with will reduce their

by Japanese paper-makers and as

is easy to burnish is necessary.Wolbers

resin has good pigment wetting quality.

retouching acrylic paintings.

permanency and lightfastness .

adhesive in paper Conservation for

found that unpigmented Aquazol 50

Also, the colours can be used to make



Gamblin® opaque




for artists use. The colour strength is

The brand Lascaux have a unique

decades. In retouching the purified

and 500 increased scattering of light

crisp brush-strokes by using with a

with traditional mastic are composed,

achieved by using Aquazol® as binder.

acrylic-modified tempera paint which

extract is used because is colourless

and reduces gloss degree

fast evaporating solvent and working

according with manufacture, of three

This watercolour is being tested due to

can be used as a retouching medium.

and produce a clear and a very matte

replicate simple layers.

can be reduced by using slower

ingredients: pigments, mastic resin,

the fact that conservators have been

There are 34 hues available. The

retouching medium very useful for

evaporating solvent

and selected hydrocarbon solvents.

using Aquazol® since 1990´s. There’s

colours have brilliance and depth and

monochromatic contemporary art,

no significant colour change, they

the pigments are lightfastness. The

especially paintings. It can be mixed

are not toxic and have lightfastness

dried film is velvety and elastic but

pigments. But due their viscosity and

. Only


Viscosity can also change with the

The analyses carried out by the

The four most popular retouching

solvent. Using the solvents mention

National Gallery of Art, Washington,

with pigments. It is very good for

colours are the Gamblin® Conservation

above, the paints normally dry up

DC, in 2000 [13], confirm the presence

remains water soluble. The paints have

mimicking “stained” canvas. For that



extremely quickly is needed to

of mastic gum, and according to

bad behaviour with high levels of HR,

covering power and can be applied

after preparation Funori can be taken

Conservation Paints, the Maimeri®

frequently replace solvent. Cover

Ameringer [14] and Szmit-Naud [15], the

they are not being used as a retouching

over a various types of substrates.

straight from fridge and brushed

Restauro Restoration Colours and

retouching paint on the palette

analyses carried out in 1989 by the

1.2 Solvent binder solutions



material. Also, they can be very glossy.

Water Resoluble Acrylic Medium

onto canvas and dabbed pigment

RestaurArte® Retouching Colours.The

with melinex helps to slower the

Canadian Institute of Conservation

Besides tube watercolour there are

is another solution provided by

into wet medium. Also, lower film of

Gamblin® paints consist of Laropal®

evaporation of the solvent.

revealed the presence of several

other types of watercolour suitable for

Lascaux®. Is colourless. It can be mixed

Funori isolates the pigment from the

A-81, a yellowing-resistant aldehyde

retouching as watercolour markers.

with dry pigments to make pains

underlying canvas. The glossy can be

resin with low molecular weight

Ana Bailão | Liliana Cardeira





stabilizers, such as aluminium, silica, clay,

the Kremer® Retouching Paints

and wax. In 2003 Szmit-Naud found

Mixing and matching. A survey of retouching materials


the addition of calcium carbonate, an

Resin Colour. Although more stable

of RestaurArte® paints. About their

art with smooth and matte surfaces.

Watercolour stick is more one dry

surrounding a damage which can

extender, in some of the colours.

and yellowing resistant than triterpene

application, some paints have an excess

The retouching’s may also be a slight

solution. Creates a transparent and

protect the paint from the abrasive


resin, over time loses solubility due to

binder, which makes it difficult to

tonal darkening of the light colours

luminous paint over the white filler

potential of the filler when shaping,

appearance and no change in the

auto-oxidation and become brittle [15, 16].

evenly distribute the paint (earth, white

which can be minimized by avoiding

with can be smooth by a moistened

texturing and reducing fill material.

shades after drying. However, the rapid

According to the colorimetric studies

titanium, red cadmium and ultramarine).

mixtures of paints and keeping the

brush. Is important to check the

Is important to test the surface with

evaporation of the solvents affects the

of Sánchez-Ortiz and Micó Boró, cobalt

The paint is pasty. It is essential to make

retouching slightly lighter and less

permanency of the pigments used

the masking material to insure that do

gloss after application to the surface,

blue may become slightly violet and

a good dissolution with the solvent to

saturated compared to the original.

because the lightfastness can be

not leave stains. The mask should be

and it is necessary to add more resin.

some colours show whitening. They

obtain a smooth paint film. Another

The fact that the copolymer creates

reduced in paints with multiple

done with temporary and reversible

The intensity of the brightness varies

are considered to be less stable to the

feature of this range of colours is the

an uneven film on the surface causes

pigments .

material like the dispersion of natural

depending on the pigments. One of

degradation of light and also insoluble in

matte result of the paints.

the incident light to be diffuse

the advantages of Maimeri® Varnish

non-polar solvents





Colours is the ability of dark tones to

Conservators can handmade paints





with many binders, besides buying


rubber in water by Royal Talens®

resin are recently sold by Gamblin®

or the Methocel® (A4C and A4M)

in sets of 12 colours. Can be used for

range developed by Dow® Chemical

filling losses in paint. Can be an option


the ones ready-made.

One of the main disadvantages of

Srl. According to the manufacturers,

B-72 (PB-72) is one of the options.

There are many dry solutions

for monochromatic and smooth

Maimeri® Varnish Colours is the

the paints are produced with pure

PB-72 is a copolymer of methyl

for retouching purposes. The dry

surfaces. The material is manipulated


proven yellowing of the mastic resin

pigments and ketonic resin, not

methacrylate and ethyl methacrylate.

powder pigments can be used as

using moderately heated tools to

Comprises Paraloid® B72 resin, a

over the years. Colours such as

specifying which one, dissolved in

The commercial resin is sold in the

they are over a damage surface.

quickly fill losses (c. 50 degrees). The

amine light stabiliser and a bulking

ultramarine blue, ivory black, yellow

essence of turpentine.

form of regular small translucent

They can be applied dry over a layer

fill can be sculpted but is not easy to

agent of fumed silica. Sold as a set

The physicochemical and mechanical

stones. It is elastic and resistant

of JunFunori® or water resoluble

manipulate with a hot pointed or flat

of 8 gels providing a range of media

[13, p. 57]


properties are similar to the Maimeri®

to oxidation, light, hydrolysis and

Medium already mention in the text.

head spatula and it is hard to direct

that varying in concentration of

white gets more yellow and pigment

Restoration Ketonic Resin Colour,

moderate heat. Is also transparent,

Other option is the mica pigments,

adequate amounts of the material

PB72, hardness, softness of the gel

paints with high absorption power,

occurring more chromatic alterations

with high mechanical strength and

or iridescent pigments. They are sold

into small fills.

and drying time (depends of the

change more easily

. In addition to

after the retouching process. For

reversibility and can be dissolved in

as powder pigments and they can be

The conservator can also use the

solvents). Three solvents are used:

the chromatic alteration, there is also

example, the earth pigments may turn

acetone, isopropyl alcohol, diacetone

added to watercolours or other kind

stick pastels. They are easy to apply

Dowanol® PM (fast evaporation),

cracking in the paint films. Another

slightly orange; cadmium red slightly

alcohol, among others, and slightly

of paint or binder.This pigments works

through sponge, rubber spatulas. Can


disadvantage is solubility. Initially, the

bluish-green and chromium oxide green

soluble in ethanol.

in small losses due to the metameric

be a solution for smudge surfaces

evaporation) and Dowanol® DPM

paints were soluble in a variety of

may change to violet. Because most

effect caused by the small crystals.

[19, 20] as well as the PanPastel®

(slow evaporation rate), all glycol

solvents, including white spirit, xylene,

colours tend to darken, the paints are

considered stable and durable in the

Caran D’Ache® Luminance 6901

Colorfin LLC.

ether type solvents.

toluene and isopropanol. However, as

considered to be very unstable to light

long term. The resin film, after drying,

Lightfast Pencil is a fine-art professional

the years pass they become insoluble

degradation. Also, the solubility tests

is more matte compared to the

coloured pencil and the only ones with


protection, texture

materials for the retouching paints

performed by Sánchez Ortiz and Miró

natural resins or polycyclohexanones,

info about lightfastness of the colours.

and appearance. Most modern and

is possible to use mica or iridescent

Due to the alterability of colours

Bocó, using three solvent mixtures of

but does not require the addition of

This type of material can be used, for

contemporary paintings do not have

pigments, pipe clay or caulin and

Maimeri® launched the same colour line

the Paolo Cremonesi protocol, of low,

a plasticizer or any other additive,

example, in paper support. The pencils

a surface coating and fill material

methycellulose, among others. Bulking

in 1998, replacing the natural resin with

intermediate and high polarity, proved

just more resin. This characteristic is

have an effortless application without

can be abrasive. For this problem

agents are added to paint to increase

ketone, Maimeri® Restauro Ketonic

to be ineffective in the dissolution

suitable to retouch contemporary

creating traces over the surface.

conservator can use a masking paint


ochre, alizarin and viridian green change significantly in tone



[13, p. 58]

Ana Bailão | Liliana Cardeira





Individual sticks of pigmented wax-

Colours line is marketed by Bresciani®

match films of aged black oil.









But there are other solutions with











To finish, as opacifiers and bulking




Mixing and matching. A survey of retouching materials






influence other desirable properties. 4. CONCLUSIONS There are many materials for retouching. All have its individual properties,



disadvantages, which can also be useful in some cases depending on the surface of the artwork. The best materials are the ones non-toxic, stable to temperature and humidity, resistant to biological attacks and



[1] BAILAO, Ana - Terminologia associada à

Painting Conservation Catalog. Vol. III: Inpainting.

50 (3) (2005). p. 193. https://doi.org/10.1179/

materials. It all depends on the object

conservação e restauro de pintura. Conservar

USA: American Institute for Conservation. The


Património. 18 (2014) pp. 55-62. doi:10.14568/

Paintings Specialty Group, 2011.

lightfast. There



and the conditions where it will be exposed. But having the conservator all these materials available became possible the matching of the original colours.

cp2013010. [2]




International Conference youth in Conservation

GLINSMAN, Lisha; MAINES, Christopher A. –

Sandra – From the laboratory to the resto-


An investigation of the photochemical stability

rer studio. Practical inpaint applications with

(ed.) – Conservation of Easel Paintings. Oxford:

oxazoline): A New Water and Organic Soluble

of urea-aldehyde resin retouching paints:

commercial colours of synthetic resins. In V Con-

Butterworth-Heinemann Ltd, 2012.

Adhesive. In GLASS, J. Edwards - Water-Soluble

removability tests and colour spectroscopy. In

gresso Internazionale “Colore e Conservazione”, Le

Polymers. Washington, D.C: American Chemical

ROY, Ashok; SMITH, Perry, ed. – Tradition and

fasi finali nel restauro delle opere policrome mobili.

Society, 1986, pp. 425-433,Vol. 213.

innovation: Advances to conservation. London:

Cesmar7, Saonara: Il Prato, 2011, p. 160.

[9] CHIU, Thomas T.; THILL, Bruce P.; FAIRCHOK, William




[6] DOMMERMUTH, Jean – Hand-Mixed.

Spain, entitled Using watercolour markers in

Aqueous Binding Media: Egg Tempera. In

chromatic reintegration: a case study and at 4th

METZGER, Catherine A.; MAINES, Christopher;

International Meeting on Retouching of Cultural



Mary; DUERBECK, Deborah - Poly (2-Ethyl-2-

Heritage, RECH 4, Split, Croatia, entitled Using

Conservation Catalog. Vol. III: Inpainting. USA:

Oxazoline): A New Conservation Consolidant.

watercolour markers in chromatic reintegration.

American Institute for Conservation. The

In DORGE, Valerie; HOWLETT, F. Carey, ed.

Proprietary. Solvent-Based resins: Low Molecular

1-13. Disponível

Paintings Specialty Group, 2011, p. 104.

- Painted Wood: History and Conservation. Los

Weight (LMW) resins. In METZGER, Catherine

stable/1506186. Consultado em 01 de Dezem-

Angeles:The Getty Conservation Institute, 1998,

A.; MAINES, Christopher; DUNN, Joanna

bro de 2017.

pp. 514-527.

(compilers) – Painting Conservation Catalog.

[18] PERRY, Roy A. – Retouching damaged


Vol. III: Inpainting. USA: American Institute for

Modern Art. In Conference 2000: Retouching

R.; MASSCHELEIN-KLEINER, L. – Comparación entre






reintegración. Revista PH. 16 (1996), pp. 63-65.



[7] BAILAO, Ana Maria dos Santos - Avaliação Colorimétrica da Alteração de Cor de Alguns Guaches e Aguarelas Utilizados na Reintegração

[10] WOLBERS, Richard C.; MCGINN,


International Institute for Conservation of

of Varnishes on the Appearance of Paintings.

Historic and Artistic Works (IIC), 2000, pp. 53. [13]

AMERINGER, Charlotte


[17] RIE, E. René de la Rie – The Influence

Studies in Conservation. 32 (1) (1987), pp. em: http://www.jstor.org/


Cromática de Bens Culturais. In CALVO, Ana;

GAMBLIN, Robert; RIE, E. René de la –

Conservation, The Paintings Specialty Group,

Filling. Oxford: Association of British Picture Re-

GUEROLA,Vicente – El estuco en la restauración

VIEIRA, Eduarda (Coord.) – Matrizes da Investi-

Development of a new material for inpainting.

2011, p. 195.

storers, 2000, pp. 19-22.

de pintura sobre lienzo. Criterios, materiales y

gação em Conservação e Restauro I. Porto: UCP/

In ROY, Ashok; SMITH, Perry, ed. – Tradition and

[14] SZMIT–NAUD, Elzbieta – Reasearch on

[19] CHIANTORE, Óscar; RAVA, Antonio –

procesos. Valencia: Universidad Politécnica de

CITAR, 2014, pp. 13-41.

innovation: Advances to conservation. London:

Materials for easel Painting Retouches: Part 1.

Conservare l´arte contemporanea: problemi, meto-

[8] GEIGER, Thomas; MICHEL, Françoise -

International Institute for Conservation of

The Picture Restorer. 23 (2003), pp. 6, 7.

di, materiali, ricerche. Milano: Electa, 2005, pp.

METZGER, Catherine A.; MAINES,

Studies on the Polysaccharide JunFunori Used to

Historic and Artistic Works (IIC), 2000, pp. 111

Christopher; DUNN, Joanna (compilers) –

Consolidate Matt Paint. Studies in Conservation.






Valencia, 2004. [4]

Ana Bailão | Liliana Cardeira



of Cultural Heritage, YOCOCU 2016, Madrid,



The Picture Restorer. 24 (2003), pp. 5-9.


[5] STONER, Joyce Hill; RUSHFIELD, Rebecca


[12] RIE, E. René de la; QUILLEN LOMAX,

[15] SZMIT-NAUD, Elzbieta – Research on

139, 291.

Materials for Easel Painting Retouches: Part 2. Mixing and matching. A survey of retouching materials


Keywords Fernando Mardel; Painter-restorer;


Chromatic reintegration; Restoration; Painting.

1. INTRODUCTION In Portugal, until the middle of the third quarter of the 20th century, painting restoration was performed by



background was in painting. After

Carolina Rodrigues Ferreira (1, 2) | Fernando António Baptista Pereira (1) | António Candeias (2, 3) | Mercês Lorena (3)

1980 emerged the first restoration courses, becoming this activity a

that in

Fernando the


Mardel of



and restoration in Portugal. First collaborating in the Luciano Freire (1864-1934) studio

, until he


became responsible for the painting restoration of the Portuguese State.

Josefa Torrado Fernandes [7].

profession with a specific training . [1]

Until the end of the 19th century the restoration of paintings resulted for




or partially. These overpainting’s were aimed at the improvement of the state of conservation, or iconographic canon changes . It is only at the end [2]

of the 19th century that we witness


a change in the restoration criteria,

Fernando Mardel (1884 - 1960), was a Portuguese painter-restorer of the 20th

for the original painting. Thus, the

century, pioneer in the interrelation between science and art, concerning the

chromatic reintegration begins to

conservation and restoration of paintings, in Portugal. Among many of his works that are worth mentioning, the restoration of the Flemish paintings of the 15th and 16th centuries, belonging to the painting collection of the Sacred Art Museum of Funchal (MASF), in Madeira Island, are one of the most important. The aim of this paper is to present Mardel´s options for the reintegration of the Flemish paintings of the MASF.

particularly concerning the respect

develop, being limited to the areas of loss and wear, not overlapping the original painting

, first with the


mimetic technique and them with the differential techniques [4]. It is in this context of change

According to some authors

, F.


Mardel attended the painting course


at the School of Fine Arts of Lisbon.

the most part in overpainting, totally 1. C  entro de Investigação e de Estudos em Belas-Artes|Faculdade de Belas-Artes da Universidade de Lisboa; Largo da Academia Nacional de Belas Artes, 1249-058 Lisboa; E-mail address: carolinaferreira80@gmail.com; fernandoabpereira@gmail.com 2. L aboratório HERCULES |Universidade de Évora; Palácio do Vimioso, Largo Marquês de Marialva, nº8, 7000-809 Évora, Portugal; E-mail address: candeias@uevora.pt 3. L aboratório José de Figueiredo | Direção Geral do Património Cultural; Rua das Janelas Verdes, 1249-018 Lisboa; E-mail address: merceslorena@gmail.com

Figure 1 • Portrait of Fernando Mardel in the atelier of the old Institute of Examination and Restoration of Works of Arts (Boletim do Museu Nacional de Arte Antiga, Fac. III,Vol IV, Lisboa, 1962).

2.1 Biographical data

Fernando Mardel de Araújo (Figure 1), was born on November 22nd, 1884 in Lisbon , and died in the same city in [6]

June 28th, 1960 , with 76 years of age. [7]

There is not many information documented




family life. He is the adopted son of Júlio Mardel (1855-1928) an important archaeologist of his time, who contributed to the history of Portuguese heritage



In the

homage of his friend and co-worker João Couto (1892-1968), there is a reference to a sister called Joana

However, no official documents have been found so far in the archives of the institution, such as the process of enrolment in the course, or a certificate of attendance at classes and exams. But it is not surprising that he had been in contact with the School environment from a very early age; influenced by his father, a member of the National Monuments Commission of the National Academy of Fine Arts of Lisbon, situated in the same building as the School. F. Mardel’s talent for painting, caught the attention of L. Freire, who taught there, and made him his disciple.

In 1910, L. Freire became a member

of Restoration in 1949

was possible to observe the mimetic

of the Commission for the Inventory

he observed the new method of

technique made by F. Mardel in these

and Improvement of Ancient Paintings,

chromatic reintegration made by


and was responsible, until 1933, for

Cesare Brandi in the mural painting

Still from the heritage of Madeira

the painting restoration at the Art and

of Lorenzo da Viterbo in the Capella

Island, he intervened in a set of Flemish

Archeology Council Office, installed

Mazzatota of the Church Santa Maria

paintings of the 15th and 16th centuries,

Araújo once again accompanied

The analytical study of the paintings

in the same building of the National

della Veritá .

currently belonging to the collection of

by F. Mardel, and were exhibited in

is still in progress at the HERCULES Laboratory of the University of


the Sacred Art Museum of Funchal [14].

the Sacred Art Museum of Funchal,

. In his team he count with the

formation, but it is with João Couto that

It is on these interventions that we will

inaugurated on July 1st of that year.

participation of F. Mardel, Luís Ortigão

his professional development is evident.

make a brief analysis of the chromatic

The installation of the paintings were

reintegration made by F. Mardel.

of the responsibility of F. Mardel




João couto defended that for conservation and restoration of the

Moreira da Cunha (1897- 1970?). F. Mardel, in 1934, at the age of 50, and until his death, was responsible for the restoration of the Portuguese





were in Lisbon, they were exhibited

knowledge scientific of the object.


twice in the National Museum of


Ancient Art. The first in 1949, before






professional career always applied the

restoration workshop at the National

available scientific means to assist him

the 16th International Congress of

Museum of Ancient Art, where

in the decisions making processes.

Art History


paintings. First, in

National Academy of Fine Arts of Lisbon

the restoration, in the context of

FUNCHAL 3.1 Historical context

was transferred the atelier of the

This set of paintings were sent to 2. 2 His work

texture of the filler mass, as usual in

Figure 3 • Imitation of the network of cracks in the leg of Saint James in the painting Our Lady of Amparo (MASF 39).

, and the second in


1952, after the restoration

, with


Lisbon in 1949, on board of the ship

the presentation of the conservation

The intervention consists in the treatment of the wooden supports and the paint layers. The reintegration was done in two phases.The first phase consisted of the application of the underpaintings with varnish and the second phase was with egg tempera. F. Mardel used the mimetic technique

. And later, at the Institute

Among many of the restoration

Angola with the accompaniment of F.

and restoration process, within the


of Examination and Restoration of

works he has done, it stands out

Mardel, who travelled to Madeira to

scope of ICOM 5th Conference of

Works of Art, the first building in

the intervention in the paintings

supervise the packaging and transport


to make the intervention invisible,

Europe to be built for this function, in

that integrated the exhibition of the

of the paintings.

1940. It was located in the annexed

Primitive Portuguese in 1940, which

The intervention took place between

ground of the National Museum of

earned him the commendation of the

1949 and 1955 at the former Institute

reintegration – materials and

Ancient Art

Officer of the Order of Saint James

of Examination and Restoration of

reflectography and x-ray (made by


in 1941

Works of Arts

Luís Piorro, at the José de Figueiredo


, presently José de


Figueiredo Laboratory, in Lisbon.

and were carried

The conservation reports on these

there were four paintings from the

out following the work for the

paintings, with the signature of F.

, which

16th century altarpiece of Funchal’s

safeguarding of the pictorial heritage


allowed him to have contact with

Cathedral in Madeira Island: Christ

of the Madeira Island, developed by

he, unlike is master L. Freire, did not

other restoration practices and to

praying in the garden; Annunciation;

Manuel Cayola Zagallo (1905?-1970),

documented extensively his work.

improve his technical skills.

Abraham and Melchizedek; and The

between 1933 and 1949

However there is information that let

In 1938, F. Mardel was a fellow of the Institute for High Culture


He went to Rome to attend the Second



. In these interventions


gathering of the Manna. Recently with a new intervention in 2013/2014

, it





In 1955, the paintings returned to Madeira in the ship Carvalho de

Carolina Rodrigues Ferreira | Fernando António Baptista Pereira | António Candeias | Mercês Lorena

in all of the paintings. The goal was

reproducing the colour and texture of the surrounding areas (Figure 2).

3.2 Fernando Mardel´s chromatic

, are poorly developed, as


us know the treatments to which the paintings were submitted.

Évora. The main goals are the identification of the materials applied in the intervention (fillers, pigments and mediums), and the stratigraphic

During the time that the paintings

work of art, it is necessary a previous This is why F. Mardel in his

(Figure 3), and not with the treatment such cases [20].

L. Freire was important in his


the surface painting with the retouch

Figure 2 • Mimetic retouching of a lacuna located in the red tunic of the painting Saint James (MASF 28).

Academy of Fine Arts of Lisbon [10]


reproduces the crack networks in

, where


With surface examination, infrared

Laboratory/DGPC), it is possible to affirm that the areas surrounding the gaps were respected, in others words, the retouching does not extend over the original painting. Although, there is the hypothesis of this happening in one or another situation. In









intervened by F. Mardel. The expected results, compared to the information in the reports, will allow a complete characterization of its technique: how he applied the colours (mixed in the palled or overlapped) and pigment identification. Although the mimetic technique is mainly adopted by F. Mardel, in the Triptych of the Incarnation (MASF 32), it is observed another solution for the retouching. This triptych had been mutilated in the wooden support when it was transferred from the original church, Nossa Senhora da Encarnação, to the church of São Martinho, in order to adapt to the new altarpiece structure

. In addition


to the mimetic retouching, similar to the other paintings, in this triptych we observe a differentiated or visible technique [20], in the adapted areas.

Fernando mardel, a portuguese painter-restorer. Retrospective of his retouching work


the collection of the Ricardo Espírito

predominant tone of the reconstituted

the reconstitution of the missing parts

perception is directed to the painting

“in order to avoid making an entirely

Santo Foundation

. In this painting

drawing, it is possible to observe

of the Triptych of the Incarnation

and not to the retouched areas.

new painting in this added portion, it

Abel de Moura used the sgraffito

others colours, namely in the back

(MASF 32).

was more convenient to complete

technique with lighter shades than

panels that represent St. Antony and

the drawing in a sepia tone of neutral

the original colours .

St. Bartholomew, where the carnations



respect for the integrity of the

and frame are coloured with the same

reconstruction of the missing parts

painting, meeting the spirit of the

tone as the original (Figure 6).

of the Triptych of the Incarnation,

intervention already advocated by his master L. Freire.

F. Mardel in the report states that

colour only to give a more agreeable set to the painting”


In the Triptych of the Incarnation


F. Mardel´s concern not to overlap




differentiated in

. However, it

the adopted solution is similar. The

does not make reference to whom

reconstruction of the drawing is

In some areas of the drawing it is

probably it’s not F. Mardel author

carried out this work.

achieved by extending the lines

used the sgraffito technique to fill the

–, the accomplishment of this work

(Figure 4).

background (Figure 7).

under his responsibility, demonstrate


Not excluding the hypothesis of

the original shows that he reveals’

the concern to introduce new

having been F. Mardel to carried out

Even though the lines of the pictorial

this work, it is also possible that it

composition are respected, there is no

was done by Abel de Moura (1911-

reference how would it be. We can

?), his successor, which by that time

observe the creativity and personal

The technical option of chromatic

used by F. Mardel aims to go unnoticed

already collaborated in the Institute. In

taste from the author when he draws

reintegration used by F. Mardel in the

by the observer, its intention is not to

1949 he made a similar intervention

a snail and vegetation (Figure 5).

Flemish paintings of the Sacred Art

create a false historical.


techniques. The mimetic chromatic reintegration

in the Triptych of St. Bartholomew,

The drawing is done in black over a

Museum of Funchal was the mimetic

He pretends that the intervention

Pieta and St. Francis, belonging to

sepia background. Although this is the

reintegration, with the exception of

be unnoticed, so that the observer’s

Figure 4 • Reconstitution of the painting in the lower part of the Triptych of the Incarnation (MASF 32).



Figure 5 • Detail of the reconstitution in the lower part of the Triptych of the Incarnation (MASF 32).

Carolina Rodrigues Ferreira | Fernando António Baptista Pereira | António Candeias | Mercês Lorena

Figure 6 • Reconstitution of the painting in the back panel of the Triptych of the Incarnation (MASF 32).

Figure 7 • Detail of the sgraffito technique to fill the drawing in the back panel of the Triptych of the Incarnation (MASF 32).

Fernando mardel, a portuguese painter-restorer. Retrospective of his retouching work


REFERENCES [1] FIGUEIRA, Francisca – A disciplina/

[9] FLOR, Susana - Fernando Mardel de

da Junta Geral no âmbito do Património

profissão de conservação e restauro: uma

Araújo. In 100 Anos de Património, memória e

Cultural, In Junta Geral do Distrito do Funchal

ciência recente e o seu desenvolvimento em

identidade. Lisboa. 2010, pp. 211-212.

(1836-1976): Administração e História. Arquivo

Portugal. Conservar Património, nº 21 (2015),

Regional da Madeira (2016), pp. 327-336.

acerca do tratamento da pintura antiga em

[17] COUTO, João; ZAGALLO, Cayola -

[2] SERRÃO, Vítor - Renovar, repintar e

Portugal segundo notas tomadas no período

Exposição Temporária das Obras de Arte dos

retocar: estratégias do pintor-restaurador em

da execução desses trabalhos. In Conservar

Séculos XV e XVI da Ilha da Madeira, Catálogo,

Portugal desde o século XVI. In Conservar

Património, Nº 5, (2007), pp. 9-65.

Lisboa (1949).

pp. 39-51.

[11] CURVEIO, Alexandra - Da Oficina de

[18] COUTO, João; ZAGALLO, Cayola

[3] CRUZ, António – O restauro de pintura

Restauro de Luciano Freire ao Instituto José de

- Pinturas dos Séculos XV e XVI da Ilha da

em Portugal no tempo de Luciano Freire. In

Figueiredo. In100 Anos de Património, memória

Madeira (Depois do seu restauro), Catálogo,

100 anos de património, memória e identidade.

e identidade. Lisboa; 2010, pp. 175-180.

Lisboa (1955).

Património, Nº 3-4 (2006), pp. 53-71.

[12] COUTO, João - Painéis Flamengos da

[19] MARDEL, Fernando, “Relatórios das

[4] BAILÃO, Ana; HENRIQUES, Francisco;

Ilha da Madeira. Seu merecimento, valorização

intervenções das pinturas da Ilha da Madeira”,

CABRAL, Madalena; GONÇALVES, Alexandre

e conservação. Funchal, Edição da Junta Geral

manuscritos, Arquivo do Laboratório José de

– Primeiros passos de maturidade a caminho

do Distrito Autónomo do Funchal, 1955, pp.

Figueiredo (1955), nº processo: Rest. 870; Rest.


16- 32.

Rest. 967; Res. 969; Rest. 970; Rest. 975; Rest.

Lisboa, 2010, pp. 117-122.




em pintura de cavalete em Portugal. Geconservación, nº 1 (2010), pp. 128-141.

[13] FERREIRA, Carolina; GOMES, Sofia, NASCIMENTO, Glória; LORENA, Mercês;

976; Rest. 977; Rest. 978; Rest. 980; Rest. 981; Rest. 983. (2015-12-3)

[5] LEANDRO, Sandra – O mito do

CANDEIAS, António – Conservação e

[20] BAILÃO, Ana – As técnicas da

recriador: Luciano Freire e os trabalhos de

Restauro das pinturas do retábulo da capela-

reintegração cromática na pintura: revisão

conservação e restauro da “Pintura Antiga”. In

mor da Sé do Funchal. Contributo, no

historiográfica. In Ge-conservación, nº 2 (2011),

40 anos do Instituto José de Figueiredo. IPCR,

contexto contemporâneo da preservação,

pp. 45-63.

Lisboa (2007), pp. 65-81.

defesa e valorização do património cultural.

[21] MARDEL, Fernando, “Relatório de

[6] Grande Enciclopédia Portuguesa e

In O retábulo no Espaço Ibero-Americano.

intervenção do Tríptico de Nossa Senhora

Brasileira, Vol. 16. Lisboa: Editorial Enciclopédia

Forma, função e iconografia, Vol. 2 (2016), pp.

da Encarnação”, manuscritos, Arquivo do

Lda., p. 272.


Laboratório José de Figueiredo (1955), nº

[7] COUTO, João - Homenagem a Fernando

[14] PEREIRA, Fernando A. B.; CLODE, Luíza

Mardel. In Boletim do Museu Nacional de Arte

– Arte Flamenga: Museu de Arte Sacra do

Antiga (Fac. III, Vol. IV), Lisboa, 1962.

Funchal. Funchal, Edicarte (1997).

[8] CUSTÓDIO, Jorge – Júlio Carlos Mardel

[15] ZAGALLO, Cayola - As Pinturas dos

de Arriaga Velho Cabral da Cunha (1855-

Séculos XV e XVI da Ilha da Madeira, Academia

1928). In 100 Anos de património, memória e

Nacional de Belas Artes, Lisboa (1943).

identidade. Lisboa, 2010, pp. 78-80.


[10] VÁRIOS - Elementos para um relatório

processo: Rest. 977 (2015-12-3). [22]





Portuguesas – Guia. Fundação Ricardo Espírito Santo, Lisboa: 2001, p. 91.

[16] GUERRA, JorgeValdemar – Intervenções

Carolina Rodrigues Ferreira | Fernando António Baptista Pereira | António Candeias | Mercês Lorena

Nome artigo


Keywords Predella; Vandalism;


Mimetic retouching; Reconstruction.

1. INTRODUCTION The three small panels of the Budapest Museum of Fine Arts are attributed to Giovanni Antonio Bazzi, called Il Sodoma (1477–1549), and

his workshop (fig. 1). The paintings depict scenes from the Passion: the Capture of Christ (36.3 × 61.8 × 1.8 cm, inv. no. 1230), the Flagellation

1890s from two different Italian art dealers [2], and it was only after their recent restoration that they were physically rejoined.

Ágnes Kuna | Tímea Bakonyi | Erdei Gábor  useum of Fine Arts, Conservation Department; Dózsa György út 41, H-1146, Budapest; E-mail address: agnes.kuna@mfab.hu, timea.bakonyi@mfab. M hu, gabor.erdei@mfab.hu Figure 1 • Giovanni Antonio Bazzi, called Il Sodoma, and his workshop: three fragments of a predella, c. 1510, before restoration. Old Masters’ Gallery, Museum of Fine Arts, Budapest.

Figure 2 • Digital reconstruction of the probable original arrangement of the restored predella fragments.

(36.5 × 70.5 × 2 cm, inv. no. 1161),


and the Road to Calvary (36.4 × 61.9

Three panel paintings of the Szépművészeti Múzeum (Museum of Fine Arts) formed

the retouching in such an extreme

× 2 cm, inv. no. 1231). Scholars date

part of a Sienese predella made around 1510. The Passion scenes were painted on

case was discussed by experts

a single wooden board, which was cut in three in the past. Due to the disjointing

from both the museum and abroad.

the works to the period when the

there are some losses of the wooden support, but the recent restoration revealed

Despite some of its disadvantages

a very particular damage to the painted surface too. After the removal of the

the decision was made in favour of

darkened varnish, discolored retouches and old fillings, traces of heavy vandalism

total reconstruction and mimetic

came into view. Scratches and holes were incised with a sharp object destroying the


eyes and other facial details of the figures. The delicate question of how to execute





artist worked in Siena [1]. The panels, originally painted on a single plank of poplar wood, formed part of the predella of an unknown altarpiece. The fragments were bought in the

Phototechnical examinations and the study of cross-sections foreshadowed partial repairs but it was only after the removal of the old varnish, retouching and fillings that the true extent of the damages was revealed. All the malevolent figures in the three scenes had been disfigured by holes as deep as the wooden support and

Figure 3 • Flagellation, detail (before and after the removal of the old restoration).

A neutral retouching would make

(fig. 4). One of the reasons of this

other paintings of the same period

a pinkish adhesive layer (no. 1 on fig. 5)

it impossible to render the variety

decision is what has been discussed

and/or of the same scale.

and then gold leaf (no. 3 on fig. 5) was

of emotions. Second, since these

above regarding the importance of

While the losses of the vandalized

glued on its surface. We decided not

predella scenes will be positioned at

preserving the expressive quality of

eyes and mouths were filled in at the

to cover the remnants of this original

eye level in the museum’s permanent

the faces. Another one concerns the

level of the original ground, we did not

feature so, after executing the fillings

exhibition, undefined facial details

phenomenon of the excessive and

fill the indentations of the scratches

where necessary, we applied neutral

could disturb the majority of visitors.

systematic vandalism, of which there

so as to leave at least some traces of

retouching (matching the tone of the

Other types of visible retouching,

is no other example in our collection;

the act of vandalism that are not so

pinkish adhesive layer).

such as tratteggio or the pointillistic


indeed, they are rare anywhere else .

evident and disturbing to the viewers.

During the removal of the old varnish

technique would be inappropriate for

Some experts both in Hungary and

Preliminary research on the painting

and retouching, we also found traces

the same reasons, and also because

abroad argued that it is not advisable

technique also provided indispensable

of bole and water gilding under the

they are impossible to carry out

to display this kind of intentional



paint surfaces along the bottom and

properly in the case of small losses

damage because it might encourage

since we aimed to preserve the

the top edges of the paintings. These

similar behaviour.

following technological and historical

belong to the former engaged frame


that had already been added when




large scratches (fig. 3). The intentional

following possibilities were discussed

damage of the paintings seems to have

about the retouching method.

such as those present in the panels.

at an unknown time in the past. The

2.1. The possibility of leaving the

2.3. The advantages and the

was therefore executed by means

holes affected especially the eyes and

intentionally caused damages fully

materials of making a mimetic

of indistinguishable retouching, and a

the mouths of the figures. Strangely,


retouching and reconstruction

total reconstruction was carried out

3.1. The variation of metal

The engaged frame was subsequently

After careful consideration, the

with Schmincke® watercolor on the

decorations present on the paintings

covered with bole and gold leaves.

committee decided in favor of the total

top of the fillings1 where necessary.

Analytical examination was carried

Especially the reddish layer extended

reintegration of the losses and, where

Once the surface was varnished,


out to reconstruct the particular

onto the grounds of the painted

necessary, the reconstruction of the

the correction of the retouching

structure of the decorative strips on

scenes. As this was an interesting

details lost due to intentional damage

was executed with a varnish mixed

the left and the right borders of the

trait of the process of execution, we

with Mussini® oil paints containing a

paintings (fig. 5).The results show that

decided not to retouch the abrasions

reduced amount of binding agent.

tin leaf (no. 2 on fig. 5) was applied over

of the paint in these small areas.

The restoration of the paintings

been caused in situ by religious fanatics

in the Road to Calvary, even Christ’s eyes and mouth have been vandalized (fig. 4). There was a concensus among the museum’s restorers and art historians that accidental losses need to be retouched. The question of the intentional damages’ restoration was much more controversial.

This option did not seem safe because of the sensitivity of the original ground and paint layers. Therefore we decided against it but, of course, agreed to make a detailed, high-resolution photo-documentation of all the damages before filling the





the ground preparation was applied to the entire front of the predella.



2.2. The possibility of a visible

We aimed to reconstruct the


The restoration of these three panels was carried out by three restorers, so it was important to harmonize their work and decisions with the art historians’ opinion too. During the committee meetings, the


Ágnes Kuna | Tímea Bakonyi | Erdei Gábor





damaged faces in a manner and style


as close to that of Sodoma and his

reintegration was disapproved for

workshop as possible. We based

more than one reasons. First, the scenes

our work on the analogies of the

are depicted in a very expressive way,

undamaged faces in the same predella

whose effectiveness depends on the visibility of each figure’s emotions.

Figure 4 • Road to Calvary, detail (during and after the restoration).

and on similar heads in the artist’s

Figure 5 • Road to Calvary. Cross-section was taken from the ca. 1 cm wide decorative strips (macroscopic photo on the left) for analyzing their layers (microscopic photos on the right).

The restoration of three strongly damaged panel paintings of a 16th-century Sienese predella


NOTES 1. Composition of the putty: 10-12 % solution of rabbit skin glue, gesso di Bologna, PVAc based wood glue (Palma Fa normál) and some drops of a triple complex medium (1 part Venice turpentine, 1 part dammar varnish, 1 part linseed oil). The putty was not colored with any pigments. The surface of the fillings was isolated with a 1:5 mixture of an acrylic dispersion (Plextol B500) and water.

3.2. The treatment of the damages

2. Composition of the varnish: a solution of dammar resin in turpentine diluted with white spirit and some

caused by the disjoining of the

drops of Lefranc & Bourgeois Satin picture varnish.


Before the present restoration, the

3. We are truly grateful to restorers Tünde Réti, Mária Velekei, and András Fáy, conservator Béla Nagy, art

originally unpainted bottom and top

historians Nikoletta Koruhely, Dóra Sallay, and Georgina S. Csető, professors László Kriston, Eszter Tuzson,

borders of the panels were filled in and overpainted. After the removal of

and Anna Vihart, scientists Dóra Kesjár and Máté Szabó, graphic designer Nóra Bene, and photographer

Figure 6 • Flagellation. Detail of one hole where the panel was originally nailed to the strut. (After the removal of the old restoration and with the wooden insert)

Dénes Józsa for their help.

this old addition, the fragmented and unstable original edges of the pictorial surfaces were stabilized with putty in

the presentation of the three predella

line with the barb. Now a clear line

fragments in our new permanent

marks where the former engaged

exhibition (to be opened in 2018)

frame of the predella met the painted



the Passion scenes will have a new




After the removal of the old fillings,

common installation box, which is now

we discovered another important

in the phase of design. Thanks to the

sign of the original structure in the

restoration and the undistinguishable

Flagellation panel: two holes that

retouching of the paintings, now we

indicate where the long plank of the

are closer to the painter’s original

predella was nailed to a central strut

intention than before. Moreover,

(back-reinforcement). The


digital technology makes it possible to

paint and ground layers over the

present an extensive documentation

holes must have been lost when the

about the pictures at the permanent

predella’s parts were separated (fig.

exhibition. There will be a display

6). After the restoration, the traces

screen showing the most interesting

of these nails are visible only on the

moments of the predella’s story:

reverse of the Flagellation. On the


Work of Art. Technologia Artis 6. Prague:

[15 November 2017].

Academy of Fine Arts, 2008, pp. 152-174.

[1] See, for example, SRICCHIA SANTORO,

[2] MRAVIK, László, ed. – in Pulszky Károly

phases of conservation before and

Fiorella – Ricerche senesi 4. Il giovane

emlékének (In memoriam Pulszky Károly).

obverse, the holes were filled in and

during the restoration, as well as the

Sodoma. Prospettiva. Vol. 30, (1982), pp. 54,

Exh. cat. Budapest: Szépművészeti Múzeum,

retouched in order to maintain the

completely uncovered state, which are

58; BARTALINI, Roberto – in Domenico

1988, p. 107

uniformity of the painted surface.

the most informative photos of the

Beccafumi e il suo tempo. Exh. cat. Milan: Electa,

[3] The predella of a polyptych by Girolamo

1990, p. 246; SRICCHIA SANTORO, Fiorella –

da Santa Croce at the church of Our Lady

in ibid., p. 378 (with earlier literature); TÁTRAI,

of Spilica in Vis was damaged by extensive

KRÁL, Mario – Epithaf of Margaret (wife of

Vilmos, ed. – Museum of Fine Arts, Budapest.

vandalism. See on the official website of the

Jan Ratold). Gothic Panel Painting from the

Old Master’s Gallery. A Summary Catalogue

Croatian Conservation Institute. Available at:

Collections of the Moravian Gallery in Brno.

of Italian, French, Spanish, and Greek Paintings.


In Conference 2008: Art and Material Aspects

Budapest–London 1991, p. 111

konzer vir anje-restaur ir anje/staf2/331-

in the Evaluation of the Origin and Age of a

nature and extent of the destruction. 4. CONCLUSIONS

A digital reconstruction will show where the fragments were probably

This restoration was carried out in 2016 and 2017 with an aim to make



Ágnes Kuna | Tímea Bakonyi | Erdei Gábor

located in the original structure of the altarpiece (fig. 2).

Also the Moravian Gallery in Brno holds a panel painting, which has been extremely vandalized. HRADILOVÁ,




The restoration of three strongly damaged panel paintings of a 16th-century Sienese predella


Keywords Chromatic reintegration; Contemporary photography; Frame,



Clara M. Prieto

Fig. 1• T  emplate of the bottom right corner paint loses onto polyester sleeve (Melinex®) using a permanent marker.


Professor of conservation and restoration at ESCRBC (Escuela Superior de Conservación y Restauración de Bienes Culturales) Madrid. Spain. Independent conservator of photographs and graphic art. claramprieto@escrbc.com

During the conservation assessment it was observed an apparent paint loss in the outer side of the bottom right corner of the frame, as well as on its right side. This losses leaved naked clear wood exposed, creating a high contrast on that area and resulting

would have penetrated in the naked wood, making it impossible to reverse. Given the short deadlines of the installation of the exhibition, the intervention had to be performed on the photography already hung on the wall, in the exhibition hall.

2.1 Materials:

Filmoplast® P90 [6] Filmoplast® P90 tinted with Black Liquitex water based acrylic paint Melinex® Permanent marker Colored Pencils

on a visual impact that affects the contemplation of the photograph. All parties concerned agreed that these losses had to be retouched, but the owner institution wanted the intervention to be fully reversible. Water soluble media was suggested, but given the nature of the paint loss, any application of this type of media

A method of fully reversible inpainting for the frame is proposed, using materials and techniques available to any paper and photography conservator [1] . The technique focuses in recreating the visual experience and ensures the retreatability of the item . [2]


The inpainting, made to measure

Photography conservators are often required to assess the conditions related to


the objects prior to exhibition, either confirming the conservation reports that


accompany the items, marking new observed damages or elaborating a new

Pugliesi, 1991, belonging to the Collection

condition report. It can also happen that some minor damages had to be intervened

of the Stedelik Museum of Amsterdam.

before the exhibition of the object.

Technical data: 130x200 cm Cibacrhome®

When the photographs arrive to the exhibition area they are often suitable

print mounted in aluminium framed in a

framed for exhibition, so the assessment includes the photograph and its frame or

black wooden frame and face protected

mounting system. In contemporary photography is rather frequent the appearance

by a Plexiglass®.

of oversized objects, with the increase of deterioration risks this fact implies.






here Baltz,




and shape on adhesive paper tape (Filmoplast ® P90)


and tinted with

acrylic media, significantly diminish

2.2 Tools:

Scalpel Teflon folder 2.3 Method:

1. Draw a template of the paint loses onto polyester sleeve (Melinex®) using a permanent marker (Fig. 1). To hold it in place small pieces of Filmoplast® P90 can be used. Adhere the tinted Filmoplast® P90 to the template and cut it to shape with a scalpel.

visibility of the damaged area. The

2. Place it onto the frame (Fig. 2)

method proposed can be performed

and adapt it to the topography of

in the exhibition area, with no risks

the surface using a Teflon folder.

or interferences with the rest of the

3. Adjust the colour hue with colour

activities of the exhibition-making.


Fig. 2 â&#x20AC;˘ T  aping inpainting on the right side of the frame.

3. RESULTS AND DISCUSSION The inpainting significantly diminish visibility of the damaged area. To remove the inpainting, the patches can be peeled away from the frame leaving no residue on the area. 4. CONCLUSIONS REFERENCES The method proposed for inpainting the frame fulfilled the objective of complete reversibility. Furthermore, the intervention can be performed in the exhibition hall, meeting the timeline required. The materials and techniques used are available to any paper and photography conservator. ACKNOWLEDGEMENTS The author would like to express her sincere gratitude to Stedelijk Museum of Amsterdam and Mapfre Foundation of Madrid.

Books and articles: [1] IRVINE, R. F. Ensuring Permanence of Contemporary Photographs. Journal of Visual Communication in Medicine, 1989, vol. 12, no. 4, pp. 135-137. ISSN 17453054. [2] APPELBAUM, Barbara - Conservation Treatment Methodology. Oxford: Elsevier Ltd, 2007. p. 359. [3] ARSLANOGLU, J.; and TALLENT, C. Evaluation of the use of Aquazol as an Adhesive in Paintings Conservation. WAAC Newsletter, 2003, vol. 25, no. 2. [4] DOWN, J. L. Adhesive Compendium for




Conservation Institute, 2015 Great Britain., Museums and Galleries Commission.,Conservation Unit., [5] JORDAN, S. K. A Review of the Preservation

Literature, 1993-1998: The

Coming of Age. Library Resources and Technical Services, 2000, vol. 44, no. 1, pp. 4-21. ISSN 00242527. Website: [6]

Filmoplast P90 Technical Information.

Available Fig. 3 â&#x20AC;˘ Adjusting the colour hue of the tape inpainting with colour pencils.


Clara M. Prieto



content/uploads/2017/02/TI_04110_201651_ filmoplast_P_90.pdf [6 November 2017]

Nome artigo


“RECH4 group, University of Split, Croatia 2017” | Photo Stjepan Krešić



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After three editions in Porto, Portugal, the 4th edition of the International Meeting on Retouching of Cultural Heritage, RECH4, took place...


After three editions in Porto, Portugal, the 4th edition of the International Meeting on Retouching of Cultural Heritage, RECH4, took place...

Profile for rechgroup