Lisa Barro covered new technical information about Satista paper and related topics on preservation of Paul Strand’s Satista prints at The Metropolitan Museum of Art.
At the beginning, Barro introduced Satista paper and informed the audience that the current research is building on the previous research presented at the 2003 PMG Winter Meeting, San Juan, Puerto Rico and published in Topics in Photographic Preservation, Volume 10: Lisa Barro, The Deterioration of Paul Strand’s Satista Prints.
Satista is a silver-platinum paper introduced in 1914. It was a cheaper alternative to platinum, before palladium paper was introduced. The Strand prints on this paper at the Met show overall fading and discoloration as well as local staining. Barro mentioned that there is a slim chance that the prints under study are platinum-toned barytaless silver paper rather than Satista, but this is unlikely, based on historical information about Strand’s papers. She also mentioned that it is unclear whether or not the Satista paper itself is causing this type of deterioration. It might be that just this group of prints that Strand made is deteriorating in this way, due to the processing, storage history, or other variables. It is possible that there are Satista prints in collections in good condition, perhaps presently identified as platinum prints. Further study and more XRF data will help make those determinations.
As part of the research published in Topics in 2003, Barro concluded that the deterioration was related to sulfiding combined with finely divided silver particles and staining possibly related to residual chemistry, but there have been many questions raised by this research. Some of these questions were related to characterization of Satista paper:
- Does Satista paper have what is called a Japine surface?
- Was there bromine in Satista paper, because the patent mentioned bromine in addition to chlorine?
- Some historical literature mentions gelatin, so is it possible that there could be gelatin present as a sizing or binder?
Conservators who heard Barro speak at PMG in 2003 have since asked her practical questions related to preservation:
- Should we exhibit these prints?
- How quickly are they changing?
- How sensitive are these prints?
This talk addressed these questions by sharing new findings from analyzing 15 years of spectrophotometric data collected from Paul Strand’s Satista prints before and after exhibition, as well as performing analysis on an unprocessed Satista paper with a range of techniques: transmission FTIR, ELISA, SEM-EDX, Raman spectroscopy and XRF. (The pack of unprocessed postcard-sized Satista paper was a gift from photographer Alison Rossiter in 2010.)
In general, the analytical results of this study shed some light on the questions above. The study showed no gelatin or bromine in the Satista paper. The question about the Japine surface is as yet unanswered; whether or not Satista has a parchmentized surface is still being investigated. If it does, it is thinner than observed in other prints. Barro also showed SEM images that illustrate where the silver and platinum salts are situated in the unprocessed paper in cross-section (the silver to platinum ratio was 12.5:1), but the implications for processed prints are not yet known. While analyzing the unprocessed Satista paper provided valuable information, it is possible that there were different surfaces made by the Platinotype Company.
To answer the questions related to exhibition and change in the prints over time, they used spectrophotometric data collected over 15 years at the Met. Color monitoring of the photograph collection at the museum began in 1992. Dana Hemmenway conducted a baseline study in 1999, and today the museum continues to collect data before and after exhibition to learn more about change during exhibition and storage periods. Katie Sanderson is the primary collector of this data at the museum. She takes measurements before and after exhibition in Dmin, Dmid and Dmax areas and evaluates the data using the CIE L*a*b* color space. Barro presented the findings that the overall rate of change for Satista prints is higher than for platinum, both in storage and on display. Using data for Strand’s portrait of Harold Greengard as illustration, she also demonstrated that the rate of change is measurably faster under exhibition conditions than during periods in storage. This data is still being interpreted and studied, and some data (such as different directions of change in different areas of the print) is posing new questions. Research is ongoing, but based on these findings, the study suggests that the approach to exhibition of Satista prints should be conservative. They recommend 40 lux, a sealed package, cool storage, and color monitoring.