Harmony in Bright Colors. Memling’s God the Father with Singing and Music-Making Angels Restored

1 marie Lizet postec Klaassen & lizet and Marie klaassen Postec

1.1 God the Father with Singing and Music-Making Angels before (top) and after treatment.

TheFrames The Conservation and Framing andof Restoration Memling’s God the Father with and Music-Making of Memling’s GodSinging the Father with Singing Angels and Music-Making Angels

The current conservation studio at the Royal Museum of Fine Arts Antwerp was established in April 1999 on the initiative of Paul Huvenne and Yolande Deckers, then general director and head of collection management, respectively. A new conservation studio was much needed to guarantee state-of-the-art material care and maintenance for the paintings collection—almost 2,300 works—but at the time the museum had to make do with the small space available to accommodate it and a decent equipment budget. On the wall of this future studio where the facilities were still in the course of being developed, hung the three monumental panels of Hans Memling’s God the Father with Singing and Music-Making Angels, painted at the end of the fifteenth century for the high altar of the Benedictine abbey church in Nájera, Spain. The conservation and restoration of the Nájera panels was one of the first assignments for the newly established studio. As it happened, in spite of their importance for the museum’s collection, the panels could not be displayed in the galleries due to their regrettable visual appearance and above all the poor material condition of the paint layers necessitating an intervention without delay.

After preliminary visual examination and study of the paintings with noninvasive imaging techniques such as infrared reflectography, X-radiography and ultraviolet photography,1 the treatment of the Nájera panels started officially on July 23, 2001. On that day the international advisory committee, consisting of experts from different disciplines who were to monitor the project throughout, met for the first time.2 The ambitious conservation and restoration project actually coincided more or less with the development of the new workshop. The divergent responsibilities and sometimes hectic activities involved in

1.1, 1.10

11

1 marie Lizet postec Klaassen & lizet and Marie klaassen Postec

1.1 God the Father with Singing and Music-Making Angels before (top) and after treatment.

TheFrames The Conservation and Framing andof Restoration Memling’s God the Father with and Music-Making of Memling’s GodSinging the Father with Singing Angels and Music-Making Angels

The current conservation studio at the Royal Museum of Fine Arts Antwerp was established in April 1999 on the initiative of Paul Huvenne and Yolande Deckers, then general director and head of collection management, respectively. A new conservation studio was much needed to guarantee state-of-the-art material care and maintenance for the paintings collection—almost 2,300 works—but at the time the museum had to make do with the small space available to accommodate it and a decent equipment budget. On the wall of this future studio where the facilities were still in the course of being developed, hung the three monumental panels of Hans Memling’s God the Father with Singing and Music-Making Angels, painted at the end of the fifteenth century for the high altar of the Benedictine abbey church in Nájera, Spain. The conservation and restoration of the Nájera panels was one of the first assignments for the newly established studio. As it happened, in spite of their importance for the museum’s collection, the panels could not be displayed in the galleries due to their regrettable visual appearance and above all the poor material condition of the paint layers necessitating an intervention without delay.

After preliminary visual examination and study of the paintings with noninvasive imaging techniques such as infrared reflectography, X-radiography and ultraviolet photography,1 the treatment of the Nájera panels started officially on July 23, 2001. On that day the international advisory committee, consisting of experts from different disciplines who were to monitor the project throughout, met for the first time.2 The ambitious conservation and restoration project actually coincided more or less with the development of the new workshop. The divergent responsibilities and sometimes hectic activities involved in

1.1, 1.10

11

organizing and expanding the young studio often interfered with the work on the paintings, which needed focus and concentration. The conservators worked only two days a week on the panels and the fact that work had to be interrupted regularly in no small measure extended the period of time needed to finish the project. The major reason for the whole process lasting nearly sixteen years (2001–17), however, was the monumental size of the paintings—totalling 1.70 by 6.75 m—and the difficult and time-consuming cleaning operation.

Along with the treatment of the Nájera panels, the newly established conservation studio developed into a prolific professional workshop: the material condition of the complete paintings collection was surveyed, hundreds of paintings were given a conservation treatment and between 1999 and 2017 almost 150 paintings were restored. Close cooperation with the Antwerp X-ray analysis, Electrochemistry and Speciation (axes) group of the University of Antwerp guaranteed scientific support for the restoration projects and technical research.

The treatment of the panels was carried out in public to ensure that the paintings, which are among the highlights of the museum’s collection, would remain visible to the museum-going public.3 One of the gallery rooms was transformed into a “Memling studio,” where a glass wall enabled visitors to see the paintings and follow the progress of the conservation work. Viewing hours scheduled every three months moreover allowed the public to enter the studio and see the paintings from nearby, to ask questions and discuss the treatment with the conservators. The significant interest aroused by these view days was heartwarming.

The better part of the time the project lasted went into the cleaning of the paintings. In addition to accumulated surface dirt, degraded varnishes and discolored retouchings—quite common issues in the conservation and restoration of old master paintings—the Nájera panels were partly covered by an exceptionally thick crust of insoluble grime which was completely unknown to the conservators. The most frequently asked question during the viewing hours was how such extraordinary thick layers of grime could have formed on the surface. This question is addressed by Catherine Higgitt in chapter 8. The labor-intensive and extremely time-consuming removal of this layer and the associated research became the central issue of the complex cleaning.4 This contribution describes the broad outlines of the treatment which, with the application of the final varnish, was finished on Feb­ ru­ary 18, 2017.5 The present publication is based on the lectures delivered during the two-day symposium celebrating the completion of the 12

Klaassen and Postec

project (March 13–14, 2017), supple­mented by additional research. The symposium was organized by Dieter Lampens, coordinator of scientific research at the Royal Museum of Fine Arts Antwerp, in cooperation with Antwerp University.

Material History

▪

Unfortunately, little is known about previous treatments of God the Father with Singing and Music-Making Angels. When the panels were sold by the Spanish monastery and entered the art trade at the end of the nineteenth century, they were brought to Madrid and “cleaned.” 6 Otherwise only a few very concise records describing minor interventions executed after the purchase of the panels by the museum in 1895 are to be found in the museum archives.7 For a long time, the museum did not have its own conservators on the payroll but hired private restorers, whether or not on a contractual basis, to monitor and maintain the collection.8 Louis Leopold Maillard (b. 1848), a painter-restorer continuing the profession of his father, is recorded in the museum archives between 1882 and 1913. In February and March 1901 he described the flaking paint on the panels. His notes were annotated in another hand stating that the left panel was covered by a layer of dirt adhering strongly to the surface and harming the brightnes of the colors.9 He proposed to consolidate the paintings and to clean them with breadcrumbs but his invoice shows that he only charged the museum for the consolidation.

The Nájera panels were among the many paintings to be stored in the basement of the museum during the First World War. In the commission report of August 6, 1917, chief curator Pol de Mont points to the risks of the dark and moist conditions there, singling out Memling’s “triptych” among several paintings that suffer from mold. More generally the report mentions the widening of existing splits, locally flaking paint and yellowed areas.10 It is decided to bring the paintings up into the galleries where Paul Claes (1866–1940), recorded in the museum files between about 1913 and 1930, surveys their condition.11 In his reports he definitely mentions mold and flaking paint in all three panels, while he also indicates that the central panel has yellowed noticeably.12 Due to an attack on October 28, 1917, the paintings were removed from the galleries again, but it is not clear where in the museum they were subsequently kept.13 During the Second World War, many paintings were stored in the basement again, but this time the Nájera panels are only briefly mentioned, again in connection with mold.14

From about the 1940s until the 1990s, three generations of the “Bender family” were hired for the maintenance of the museum’s collection. Grandfather Corneel (1886–1964) worked in the museum from about 1941 to 1958, when his position was officially taken over by his son Frederik, who served until the 1980s.15 In that period, the Nájera panels are listed as “treated paintings” in the years 1952, 1977, 1979 and 1980 without any further specifications.16 The list of paintings “to be restored” in 1977, for example, contains no less than sixty inventory numbers, probably due to the period of severe drought from May to July 1976.17 In two reports from 1977 surveying the damage caused by this dry period, the right panel is mentioned because of severe lifting of paint and strongly discolored retouchings.18 The third Bender generation consisted of Corneel’s grandsons Jan and Cor, but no records connecting them to the Nájera panels have been found.

Besides the aforementioned archival records, the paintings themselves showed evidence of previous interventions. The three different kinds of filling found during the treatment most likely correspond with three different conservation campaigns.19 The cradles on the back of the panels are nowhere referred to in the museum’s archival records but based on their style and construction, wood specialist Jean-Albert Glatigny dates them to the 1950s or 1960s, long after the acquisition of the panels. This dating is also in accordance with the chronology of interventions on the frames, described in chapter 5.

One of the varnishes on the surface was a modern, synthetic one, containing isobutyl-acrylate.20 Since the use of acrylic resins as a conservation material only became widespread in the 1940s and ’50s,21 this varnish too must have been applied in the museum. In addition to

1.2

1.2 Cradle on the reverse of the left panel (779) (before treatment).

1 Conservation and Restoration

13

organizing and expanding the young studio often interfered with the work on the paintings, which needed focus and concentration. The conservators worked only two days a week on the panels and the fact that work had to be interrupted regularly in no small measure extended the period of time needed to finish the project. The major reason for the whole process lasting nearly sixteen years (2001–17), however, was the monumental size of the paintings—totalling 1.70 by 6.75 m—and the difficult and time-consuming cleaning operation.

Along with the treatment of the Nájera panels, the newly established conservation studio developed into a prolific professional workshop: the material condition of the complete paintings collection was surveyed, hundreds of paintings were given a conservation treatment and between 1999 and 2017 almost 150 paintings were restored. Close cooperation with the Antwerp X-ray analysis, Electrochemistry and Speciation (axes) group of the University of Antwerp guaranteed scientific support for the restoration projects and technical research.

The treatment of the panels was carried out in public to ensure that the paintings, which are among the highlights of the museum’s collection, would remain visible to the museum-going public.3 One of the gallery rooms was transformed into a “Memling studio,” where a glass wall enabled visitors to see the paintings and follow the progress of the conservation work. Viewing hours scheduled every three months moreover allowed the public to enter the studio and see the paintings from nearby, to ask questions and discuss the treatment with the conservators. The significant interest aroused by these view days was heartwarming.

The better part of the time the project lasted went into the cleaning of the paintings. In addition to accumulated surface dirt, degraded varnishes and discolored retouchings—quite common issues in the conservation and restoration of old master paintings—the Nájera panels were partly covered by an exceptionally thick crust of insoluble grime which was completely unknown to the conservators. The most frequently asked question during the viewing hours was how such extraordinary thick layers of grime could have formed on the surface. This question is addressed by Catherine Higgitt in chapter 8. The labor-intensive and extremely time-consuming removal of this layer and the associated research became the central issue of the complex cleaning.4 This contribution describes the broad outlines of the treatment which, with the application of the final varnish, was finished on Feb­ ru­ary 18, 2017.5 The present publication is based on the lectures delivered during the two-day symposium celebrating the completion of the 12

Klaassen and Postec

project (March 13–14, 2017), supple­mented by additional research. The symposium was organized by Dieter Lampens, coordinator of scientific research at the Royal Museum of Fine Arts Antwerp, in cooperation with Antwerp University.

Material History

▪

Unfortunately, little is known about previous treatments of God the Father with Singing and Music-Making Angels. When the panels were sold by the Spanish monastery and entered the art trade at the end of the nineteenth century, they were brought to Madrid and “cleaned.” 6 Otherwise only a few very concise records describing minor interventions executed after the purchase of the panels by the museum in 1895 are to be found in the museum archives.7 For a long time, the museum did not have its own conservators on the payroll but hired private restorers, whether or not on a contractual basis, to monitor and maintain the collection.8 Louis Leopold Maillard (b. 1848), a painter-restorer continuing the profession of his father, is recorded in the museum archives between 1882 and 1913. In February and March 1901 he described the flaking paint on the panels. His notes were annotated in another hand stating that the left panel was covered by a layer of dirt adhering strongly to the surface and harming the brightnes of the colors.9 He proposed to consolidate the paintings and to clean them with breadcrumbs but his invoice shows that he only charged the museum for the consolidation.

The Nájera panels were among the many paintings to be stored in the basement of the museum during the First World War. In the commission report of August 6, 1917, chief curator Pol de Mont points to the risks of the dark and moist conditions there, singling out Memling’s “triptych” among several paintings that suffer from mold. More generally the report mentions the widening of existing splits, locally flaking paint and yellowed areas.10 It is decided to bring the paintings up into the galleries where Paul Claes (1866–1940), recorded in the museum files between about 1913 and 1930, surveys their condition.11 In his reports he definitely mentions mold and flaking paint in all three panels, while he also indicates that the central panel has yellowed noticeably.12 Due to an attack on October 28, 1917, the paintings were removed from the galleries again, but it is not clear where in the museum they were subsequently kept.13 During the Second World War, many paintings were stored in the basement again, but this time the Nájera panels are only briefly mentioned, again in connection with mold.14

From about the 1940s until the 1990s, three generations of the “Bender family” were hired for the maintenance of the museum’s collection. Grandfather Corneel (1886–1964) worked in the museum from about 1941 to 1958, when his position was officially taken over by his son Frederik, who served until the 1980s.15 In that period, the Nájera panels are listed as “treated paintings” in the years 1952, 1977, 1979 and 1980 without any further specifications.16 The list of paintings “to be restored” in 1977, for example, contains no less than sixty inventory numbers, probably due to the period of severe drought from May to July 1976.17 In two reports from 1977 surveying the damage caused by this dry period, the right panel is mentioned because of severe lifting of paint and strongly discolored retouchings.18 The third Bender generation consisted of Corneel’s grandsons Jan and Cor, but no records connecting them to the Nájera panels have been found.

Besides the aforementioned archival records, the paintings themselves showed evidence of previous interventions. The three different kinds of filling found during the treatment most likely correspond with three different conservation campaigns.19 The cradles on the back of the panels are nowhere referred to in the museum’s archival records but based on their style and construction, wood specialist Jean-Albert Glatigny dates them to the 1950s or 1960s, long after the acquisition of the panels. This dating is also in accordance with the chronology of interventions on the frames, described in chapter 5.

One of the varnishes on the surface was a modern, synthetic one, containing isobutyl-acrylate.20 Since the use of acrylic resins as a conservation material only became widespread in the 1940s and ’50s,21 this varnish too must have been applied in the museum. In addition to

1.2

1.2 Cradle on the reverse of the left panel (779) (before treatment).

1 Conservation and Restoration

13

1.3A Detail of Music-Making Angels (780) before treatment showing the recent retouchings in the band of clouds.

numerous older and less soluble retouchings— judging by their appearance and solubility almost certainly oil-based—some of them were clearly of a recent date and executed in a modern paint, probably acrylic. These were, for example, broadly present in the band of clouds of the right panel.

In general, it appears that little has been done to the panels after the 1960s. This can be deduced from a series of photos taken by the Royal Institute for Cultural Heritage (kik-irpa, Brussels) in the 1950s and 1960s, which show more or less the same condition of the paintings as before the last treatment, with the same losses, retouchings and degraded varnishes.22

1.4 Severe flaking of paint across all three panels.

1.3

Conservation

▪

1.3b uring removal of the recent D retouchings (still visible at the bottom of the photograph) in the band of clouds.

14

Klaassen and Postec

The recent treatment started with the consolidation of the paint layers and gilding, which were severely lifting across the whole surface of all three panels. The high risk of losing original material necessitated prompt intervention. Warmed sturgeon glue23 was introduced underneath the raised paint, after which the surface was carefully flattened and secured to the ground using Japanese paper, a little bit of lukewarm air or a slightly warmed spatula. This general consolidation was not only necessary as a first aid to prevent loss of original material, but also to obtain a secure surface for the next intervention: the structural treatment of the oak panels.24 Further consolidation was carried out during the cleaning process, with the paint layers and gilding freed from dirt and thus more accessible for the glue.

Unfortunately, in spite of their excellent condition, the wooden supports had been thinned to approximately half of their thickness in order to be cradled.25 As the cradles were blocked and the restricted movement of the wood might cause tension in the panels, it was decided to unblock the sliding battens. These were carefully pushed out of the cradle and thinned, polished and coated with paraffin before they were put back. The joins between the different planks were mostly stable. A few were open at their far ends and locally re-glued.

Notwithstanding the monumental size of the panels, their precarious material condition was stabilized within less than a year after the start of the treatment. The remaining years were necessary to clean the exceptionally dirty surface of the paintings and to retouch the losses.

1.4

1.5

1.5 During consolidation of the left panel little pieces of Japanese paper (facings) protected the surface and absorbed a possible surplus of glue.

1 Conservation and Restoration

15

1.3A Detail of Music-Making Angels (780) before treatment showing the recent retouchings in the band of clouds.

numerous older and less soluble retouchings— judging by their appearance and solubility almost certainly oil-based—some of them were clearly of a recent date and executed in a modern paint, probably acrylic. These were, for example, broadly present in the band of clouds of the right panel.

In general, it appears that little has been done to the panels after the 1960s. This can be deduced from a series of photos taken by the Royal Institute for Cultural Heritage (kik-irpa, Brussels) in the 1950s and 1960s, which show more or less the same condition of the paintings as before the last treatment, with the same losses, retouchings and degraded varnishes.22

1.4 Severe flaking of paint across all three panels.

1.3

Conservation

▪

1.3b uring removal of the recent D retouchings (still visible at the bottom of the photograph) in the band of clouds.

14

Klaassen and Postec

The recent treatment started with the consolidation of the paint layers and gilding, which were severely lifting across the whole surface of all three panels. The high risk of losing original material necessitated prompt intervention. Warmed sturgeon glue23 was introduced underneath the raised paint, after which the surface was carefully flattened and secured to the ground using Japanese paper, a little bit of lukewarm air or a slightly warmed spatula. This general consolidation was not only necessary as a first aid to prevent loss of original material, but also to obtain a secure surface for the next intervention: the structural treatment of the oak panels.24 Further consolidation was carried out during the cleaning process, with the paint layers and gilding freed from dirt and thus more accessible for the glue.

Unfortunately, in spite of their excellent condition, the wooden supports had been thinned to approximately half of their thickness in order to be cradled.25 As the cradles were blocked and the restricted movement of the wood might cause tension in the panels, it was decided to unblock the sliding battens. These were carefully pushed out of the cradle and thinned, polished and coated with paraffin before they were put back. The joins between the different planks were mostly stable. A few were open at their far ends and locally re-glued.

Notwithstanding the monumental size of the panels, their precarious material condition was stabilized within less than a year after the start of the treatment. The remaining years were necessary to clean the exceptionally dirty surface of the paintings and to retouch the losses.

1.4

1.5

1.5 During consolidation of the left panel little pieces of Japanese paper (facings) protected the surface and absorbed a possible surplus of glue.

1 Conservation and Restoration

15

16

Klaassen and Postec

Before cleaning hardly any difference was noticeable between the green lining of God’s cope and the blue tunic underneath. In normal light these vestments appeared as a flat monochrome area ( a ).

Infrared, however, revealed the presence of modeling and volume ( B ), which became visible again after restoration ( C ).

Cleaning

c

 1.7 The retouchings were much larger than the actual losses and thus covered parts of the original paint layer.

Crudely executed and highly discolored, they gave the paintings a very restless and spotty appearance.

a

1.8

The varnish layers were thick, irregular and strongly yellowed. Having lost their transparency, instead of saturating the colors they formed a milky veil over large areas of the surface.

▪

b

a

 1.6

b

c

The optical condition of the paintings was exceptionally bad. The varnish layers were thick, irregular and heavily yellowed. Having lost their transparency, they no longer saturated the colors but instead formed a milky veil over large areas of the surface. What is more, they blocked the penetration of the sturgeon glue and so prevented a thorough consolidation of the paint layer.

The retouchings and overpaints present on the surface were of very poor quality. They were much larger than the actual losses and so covered parts of the original paint layer. Crudely executed and highly discolored, they gave the paintings a very restless and spotty appearance.

The removal of the degraded varnish layers and discolored retouchings was not, however, the main problem during the cleaning process.

A far more difficult issue was the crust locally present underneath the varnish which was so exceptionally thick and opaque that it almost completely obscured the original paint layer. The removal of this crust turned out to be a major challenge and the main reason for the long period of time needed to finish the project.

The different layers of accumulated dirt had huge consequences for the readability of the paintings. Before cleaning, many details were totally invisible, colors and color nuances were subdued and the sense of depth in the composition was greatly diminished, highly affecting the artistic quality of the works, which looked dull and flat. God the Father’s blue tunic and the green lining of his cope, for example, were hardly distinguishable from each other and appeared as one flat, mono­chrome dark area. The cope of angel 4 looked like a plain, brown shape without color, form or refinement and many details in the feathers of the angel’s wings were completely lost. Only technical images (infra­red, X-radiography) revealed the presence of decorative details and modeling underneath the dull, monochrome areas, for instance.

The technical images demonstrated that, in many areas, underneath the layers of dirt a much more detailed and elaborate composition was present than could be seen under visible illumination. A cleaning was absolutely necessary to restore the intrinsic quality of the paintings.

1.6

1.7

a Before restoration

b irr

c After restoration

a Before restoration

b ir

c After restoration

1.9 Before cleaning, the cope of angel 4 was merely a plain, brown shape without color, form or refinement ( a ).

The lush brocade pattern in the cope and maniple could be seen in the infrared image ( B ) and became visible again after restoration ( C ).

1.8a 1.9a

1.8b, 1.9b

1 Conservation and Restoration

17

16

Klaassen and Postec

Before cleaning hardly any difference was noticeable between the green lining of God’s cope and the blue tunic underneath. In normal light these vestments appeared as a flat monochrome area ( a ).

Infrared, however, revealed the presence of modeling and volume ( B ), which became visible again after restoration ( C ).

Cleaning

c

 1.7 The retouchings were much larger than the actual losses and thus covered parts of the original paint layer.

Crudely executed and highly discolored, they gave the paintings a very restless and spotty appearance.

a

1.8

The varnish layers were thick, irregular and strongly yellowed. Having lost their transparency, instead of saturating the colors they formed a milky veil over large areas of the surface.

▪

b

a

 1.6

b

c

The optical condition of the paintings was exceptionally bad. The varnish layers were thick, irregular and heavily yellowed. Having lost their transparency, they no longer saturated the colors but instead formed a milky veil over large areas of the surface. What is more, they blocked the penetration of the sturgeon glue and so prevented a thorough consolidation of the paint layer.

The retouchings and overpaints present on the surface were of very poor quality. They were much larger than the actual losses and so covered parts of the original paint layer. Crudely executed and highly discolored, they gave the paintings a very restless and spotty appearance.

The removal of the degraded varnish layers and discolored retouchings was not, however, the main problem during the cleaning process.

A far more difficult issue was the crust locally present underneath the varnish which was so exceptionally thick and opaque that it almost completely obscured the original paint layer. The removal of this crust turned out to be a major challenge and the main reason for the long period of time needed to finish the project.

The different layers of accumulated dirt had huge consequences for the readability of the paintings. Before cleaning, many details were totally invisible, colors and color nuances were subdued and the sense of depth in the composition was greatly diminished, highly affecting the artistic quality of the works, which looked dull and flat. God the Father’s blue tunic and the green lining of his cope, for example, were hardly distinguishable from each other and appeared as one flat, mono­chrome dark area. The cope of angel 4 looked like a plain, brown shape without color, form or refinement and many details in the feathers of the angel’s wings were completely lost. Only technical images (infra­red, X-radiography) revealed the presence of decorative details and modeling underneath the dull, monochrome areas, for instance.

The technical images demonstrated that, in many areas, underneath the layers of dirt a much more detailed and elaborate composition was present than could be seen under visible illumination. A cleaning was absolutely necessary to restore the intrinsic quality of the paintings.

1.6

1.7

a Before restoration

b irr

c After restoration

a Before restoration

b ir

c After restoration

1.9 Before cleaning, the cope of angel 4 was merely a plain, brown shape without color, form or refinement ( a ).

The lush brocade pattern in the cope and maniple could be seen in the infrared image ( B ) and became visible again after restoration ( C ).

1.8a 1.9a

1.8b, 1.9b

1 Conservation and Restoration

17