45th Annual Meeting – BPG, Art on Paper Discussion Group, June 1, “Multiple Perspectives on the Treatment of Multiples”

Multiple Perspectives on the Treatment of Multiples: Innovative thinking on the conservation of prints

Participants: Judy Walsh, Anisha Gupta, Sarah Bertalan, presenters; Rachel Freeman, Cyntia Karnes, Harriet Stratis, moderators.

This panel offered three presentations followed by a discussion that touched on how we define a group of multiples, how we determine treatment goals and exhibition parameters for the group (i.e. by looking at other examples of the same impressions or by broadening our research to include similar works), and whether or not we should strive to apply consistent treatment protocols to each object in the group.

Judy Walsh, former professor of paper conservation at Buffalo State, presented the complex and nuanced treatments of three fifteenth century copperplate engravings carried out at the National Gallery of Art. Though these works were not identical impressions, nor were they by the same artist, she identified them as belonging to the same “cohort,” meaning that they shared the characteristics of age, materials, process, and in this case, a long tradition of scholarly reference and interpretation. An impression of St. Michael Defeating the Devils from 1467 by the Master E.S. is one of only five known to exist and Man in a Fantastic Helmet c. 1470/80 is unique. The third print, The Virgin and Child by Mantegna c. 1470, was drawing particular attention due to recent revelations about its condition. Ms. Walsh outlined the restrictions placed on all three treatments by NGA curators who were concerned that the prints might deviate too much from their long-published, damaged appearances.

Though the curators at first sought minimal treatment with little to no cosmetic compensation, in each case Ms. Walsh described how she was able to present a logical argument for reducing distracting damages and finding reversible methods of completing each image based on her research into other works in the cohort. Ultimately, her creative solutions allowed the prints to retain their status as time-honored works that presented indelible marks of storied pasts, while at the same time, she was able to stabilize each work and align it more closely with the visual standard of other fifteenth century prints presented in the Gallery.

Sarah Bertalan, conservator in private practice, presented several interesting observations that she has made over the years regarding multiples printed on Van Gelder Zonen, Arches, Rives, Montval, and MBM papers. These papers all have unique characteristics and respond to treatment differently. For many nineteenth century artists in particular, Japanese papers, Arches papers, and aged papers were desirable for printing etchings and drypoints. Sometimes the publishers of artists’ editions selected papers, and some papers were marketed by their manufacturers for specific applications. Rives BFK was originally produced for photographic mounts, for example. Depending on their intended function, these papers could be bulked with fillers, additives, and/or colorants such as yellow ocher or titanium dioxide. Ms. Bertalan wanted to stress that we often don’t know what is in a paper and shouldn’t assume that we can tell by looking or testing in a discrete area only.

Common problems that she has noticed include the development of white spots, generally referred to as “reverse foxing” when Van Gelder Zonen papers are subjected to aqueous treatment, certain Somerset papers preferred by artists like Hockney and Freud turn yellow when they are placed in contact with alkaline material, and some Arches sheets, initially white or off-white, can turn a buff/yellow color over time. This she suspects is due to the presence of titanium dioxide, which is a photocatalyst.

Ms. Bertalan suggested that we don’t necessarily know how or have the means to detect all of the components of any given paper, and that typical treatments may not really be addressing the root of their problems. This lack of understanding can result in reversion or reappearance of stains post-treatment.

Anisha Gupta, Mellon Fellow at the Fine Arts Museums of San Francisco gave the final presentation of the panel in which she presented a case study of her treatment of 24 Ben Shahn lithographs that had all received extensive, but differential light exposure over the course of 23 years. All were printed on Arches ‘cover’ paper that was specifically manufactured for printing. In this case, all of the works in the group were going to be shown together and moreover, the meaning of each print was directly influenced by those on either side.

Working with a curator, Ms. Gupta determined that light bleaching would be the best course of treatment and what the optimal paper tone would be. She used a spectrophotometer to establish baseline L* values for each of the 24 works, but she said that ultimately as treatment progressed, a sense of unity was more easily achieved visually than numerically. The treatment involved bathing and light bleaching in increments of 3 hours. Though she did note that spectrophotometer readings taken of each work after treatment confirmed that the prints’ L* values had converged.

Following the three presentations, the moderators solicited questions from the audience and initiated a conversation.

Peggy Ellis, Professor of Paper Conservation at NYU, asked Ms. Gupta how she and the curator arrived at the “right color” for the paper tone of the Shahn prints and if she could remember some of the terminology that the curator had used to describe that paper tone. Ms. Gupta replied that the curator had repeatedly referred to the lightstruck prints as ‘dingy,’ and that she would like them to look “more alive.” The optimal paper tone was based on the maximum lightness that could be achieved by light bleaching the darkest paper for a set amount of time. Ms. Gupta mentioned that she thought that at some point, the treatment had hit a plateau and that had further lightening been desirable, she may have explored chemical bleaches, pH changes, or exposing the versos of the prints.

With the general topic of the risk of over-bleaching circulating, Judy Walsh speculated that many 15th century prints that look so bright white today may have been treated to a different standard (what we might now consider over-treating) in the past. She then raised the question of how to integrate current treatment standards and ethics when the challenge is to visually unify works that belong to a cohort.

Sylvia Albro, Paper Conservator at the Library of Congress, brought up the fact that many 15th century prints that have not been removed from bindings are quite white, and that contemporary books in good condition might be useful standards of reference when trying to determine “original” paper tones.

Ms. Walsh also stressed that when trying to determine how prints should look, our own experiences and visual memories are our best assets as conservators. For that reason we should be making more efforts to talk to colleagues in the field, especially those in private practice and at regional centers because they have seen and treated a volume and variety of objects that a museum conservator does not typically experience.

Antoinette Owen, Head of Paper Conservation at the Art Institute of Chicago, offered her personal experience with Van Gelder Zonen papers, saying that there is definitely “something in them” that cannot be identified with XRF, and that whatever it is causes white spots to develop when they are exposed to moisture. Ms Bertalan said that it is unlikely that you would find a measurable difference because the staining is not necessarily related to a higher concentration of iron. She put forth one theory, that perhaps during long print runs paper may have been left to soak for days prior to printing. This situation could lead to fungal growth or other latent changes. Joan Weir, Paper Conservator at the Art Gallery of Ontario, chimed in to say that as a printmaker, she had witnessed some colleagues adding formaldehyde or other biocides to their baths to prevent mold.

Shifting topics slightly, Harriet Stratis, Senior Research Conservator at the Art Institute of Chicago asked for peoples’ approaches to showing (or not showing) individual prints that are part of a series. She wanted to know how other people managed opportunities for differential exposure. Victoria Binder, Associate Conservator at the Fine Art Museums of San Francisco, replied that her institution had recently required half of an Andy Warhol edition requested for exhibition to be swapped with its counterpart halfway through the show so that all prints in the series received equal exposure. This seemed to be a common practice.

Ultimately, the consensus in the room seemed to be that a centralized library of treatment protocols and results would be invaluable. At this, an impassioned plea went up to submit text and images to the Book and Paper Wiki. To contribute to the wiki, contact BPG Wiki Coordinators, Katherine Kelly and Denise Stockman.