alkaline materials can cause cyanotypes to decolorize, bleaching away the image. The small size of Prussian blue image particles complicates aqueous treatment: the physical action of the water can wash them from their substrate. Despite their vulnerabilities, cyanotypes can be safely displayed by housing them in non-alkaline (or unbuffered) materials, limiting their exposure to light, and exhibiting them in a moderate and consistent environment. For this exhibition, all framed objects were mounted in sink mats made from 4-ply, unbuffered, high-quality mat board. 7 The sink mats were created by adhering strips of unbuffered board to the backboard to create a recess or “sink” in which the cyanotype is mounted. When covered by the mat window, the strips are invisible. Sink mats were selected because they allow air to circulate around the image. If the cyanotype fades while on display, access to air allows the image to regenerate while the gallery lights are turned off. The exhibition is on display for 3 months in a climatecontrolled gallery conditioned to 70 degrees F +/–5 and 50% relative humidity +/–5. The gallery lights are adjusted between 4–5 footcandles, which is a moderate to low amount of light. Following the exhibition, the cyanotypes will be stored in their sink mats in dark storage with access to air for several years to allow them to regain image density loss.8
Fig. 16: A 6x microscopic detail of Dow’s Flowers with Pods. Details of Dow’s Flowers with Pods and Ware’s Ficus (Figure 17) offer a close view of the finer image color and gradation Ware achieved using his process in comparison to those Dow achieved using Herschel’s process. in Ficus, the depth of the blue background and the subtle shifts in color in the leaf are particularly noteworthy.
Although the existing literature readily explores how cyanotypes are made, the medium’s inherent vulnerabilities, and how they can be safely displayed and stored, relatively little information is available about how they can be safely treated. Specifically, while it is accepted that cyanotypes are vulnerable to aqueous treatment, how vulnerable are they? A small number of publications discuss the aqueous treatment of cyanotypes, but the conservation field would benefit from more research that further defines the boundaries of aqueous treatment and how those treatments affect the stability of the medium over time.9 For this exhibition, we adopted a conservative approach, and none of the cyanotypes was treated aqueously. However, I hope to contribute to this growing body of knowledge about one of art history’s most delightfully peculiar mediums.
Fig. 17: A 6x microscopic detail of Ware’s Ficus.10
Published on Feb 10, 2016
Published on Feb 10, 2016
Cyanotypes: Photography’s Blue Period Edited by Nancy Kathryn Burns, Assistant Curator of Prints, Drawings, and Photographs Kristina Wilson...