Reprinted with permission from Infinity: The Newsletter of the SAA Preservation Section, v.9 #1, Spring, 1993, where it appeared under the title "Report on Photographic Materials." The author is a Senior Photographic Conservator at the National Archives and Records Administration.
Last year at this time, this column [the photographic materials column in Infinity: The Newsletter of the SAA Preservation Section] contained reports on two major developments in photograph preservation that resulted from NEH and NHPRC grant funding to the Image Permanence Institute for research on the stability of cellulose acetate (safety) film and protective polysulfide toning of silver images for microfilm, etc. Although the past year seems quiet in comparison, some interesting activities and research presentations at both photographic standards committee meetings and conservation conferences have taken place.
The past year was busy for the Photographic Materials Group (PMG) of the American Institute for Conservation (AIC). Two meetings were held: the annual AIC conference in Buffalo in June 1992 and the biannual winter meeting of AIC/PMG in Austin in February 1993. Between these two meetings, 31 formal papers were delivered on technical, research, and treatment topics; a number of "conservation treatment tips" were presented; and one full day was devoted to color photography (preservation, technological history, and identification) and to the increasing use of electronic photography and imaging technology with associated "hard copy" printing technology.
The conference papers will be published in Topics in Photographic Preservation, Vol. 5, 1993 by PMG/AIC. This unjuried and voluntary publication will be available through AIC this summer at a cost of $15.00-$20.00 to non-AIC members. [The price decided on was $17.50 + $3.00 postage, prepaid; call 202/452-9545 to order--Ed.].
Several presentations from these meetings should be of particular interest to archivists and are summarized below.
At the June PMG/AIC meeting, Jim Reilly presented an update of IPI research activities. IPI is now recommending and selling IPI Silverlock polysulfide toning solution to increase the image stability of silver gelatin microfilm. Some microfilm companies, e.g. MAPS, are using this formula when requested to do so.
Reilly also reported on IPI's continuing research into the effect of air pollutants on different types of microfilm, such as silver, color, and vesicular film. IPI hopes to continue and expand this research which initially has indicated that color photographic processes are far more sensitive to ozone than silver microfilm.
With funding from the Commission on Preservation and Access, IPI studied the stability of color microfilms, including chromogenic color film (Eastman Kodak color motion picture film is commonly used) and silver dye bleach color microfilm (formerly Cibachrome, now called Ilfochrome). The Commission published the results of this study in September 1992. The study showed that motion picture film color dyes will fade 30% at room temperature in 25-40 years, while the Cibachrome color film takes an estimated 200-300 years to fade the same amount. At low temperature storage in a cold vault, both types of color film have excellent stability. On a practical basis, this study illustrates that masters of either type can be preserved in cold storage. At the same time, we should recognize that any type of color microfilm being used to a significant degree may need replacement due to wear and tear long before color fading becomes objectionable. . . .
Last and most importantly for archivists, IPI now has available the IPI Storage Guide for Acetate Film. This Guide sells for $25.00 + $2 shipping and can be ordered by phone (716/475-5199) or by FAX (716/475-7230). It includes several charts that list various storage conditions, the expected time that the film will remain stable at those conditions, and a way to estimate to what extent stability may be decreased by removing the film from good storage conditions to ambient office levels. In addition, the Guide includes a rotating wheel chart that easily allows a collection manager to estimate how much "film life" can be "bought" by storing holdings at various temperature or humidity levels.
The circular chart and tables are excellent for their ease of use and wealth of information. They are valuable tools that allow an individual to weigh the tradeoffs of the cost of maintaining certain environmental conditions against the estimated increase in the life of holdings under certain of those conditions--and, as a result, more informed preservation management decisions can be made.
The Austin Conference of PMG/AIC was noteworthy for the number of presentations on electronic imaging, including the use of computer "restoration" techniques for faded color photographs (Jim Wallace of the Smithsonian) or as a replacement for the traditional copy-and-airbrush restoration method for damaged photographs.
Talks of interest to Preservation Section members included a discussion of digital image restoration by Gary Steele of Digital Techniques, Inc., of Norcross, Georgia; presentations on optical storage systems (video or digital, CD-ROM discs) by John Stokes of Stokes Imaging Services, Austin, Texas, and Gary Steel; and a talk on the revolution in photography due to electronic photography (digital or still video cameras) used by news service bureaus, newspapers, and government agencies. The impact of electronic photography on traditional photographic archives will be similar to the impact that video has had on motion picture archives--a change in technology that has resulted in a plethora of formats, format stability issues, hardware- and software-dependent media, and the disturbing fact that digital images can be easily and undetectably altered.
Stokes and Steele addressed the current optical imaging technologies and their costs. In addition, Stokes presented the results of an informal survey among institutions his business serves to determine if the use of videodiscs increased or reduced staff work and to identify the greatest obstacle to the adoption of these sophisticated research/access tools. The institutions reported that the use of optical discs reduced the handling of collections by researchers. However, staff workload grew because the resulting increase in requests for reproduction service orders led to more records being pulled.
The survey also showed that the greatest impediment to increasing the use of optical discs was not cost, which is large, but the backlog of uncataloged holdings. The creation and use of optical discs depends on catalog database information being linked to the images on the disc. Without the database, a disc is nothing more than an assemblage of pretty pictures. Although a disc can be easily filled with images, full use may lag for years as the catalog database is assembled. Personnel costs associated with cataloging may exceed the actual cost of "archiving" images onto a disc. Once records are cataloged, the production of an optical disc can be relatively straightforward.
Finally, a talk by Steve Puglia at the PMG conference covered the storage, environmental and laboratory features of Archives II, NARA's new facility in College Park, Maryland. His talk reviewed the storage conditions for various record media, design features of the compact shelving, and laboratory equipment for negative duplication.
The most recent change in standards for photographs involves the photographic activity test (PAT), which is used to determine if enclosure and housing materials will fade or stain photographs. The PAT used to be part of ANSI IT9.2-1991 Photographic Film, Plates and PapersÑFiling Enclosures and Storage Containers. The test method was changed slightly, based on work by IPI and NARA, and is now a separate standard, IT9.16 Photographic Activity Test. It is expected to be published in the winter of 1993-94.
ANSI IT9.2 now describes types of enclosures, acceptable characteristics of papers and plastics used in housing materials, acceptable designs, and the need for materials to pass the IT9.16 PAT. Changes to the PAT standard include new test methods used to evaluate the chemical reactivity of materials used for the storage of diazo film, color photographs, and for albums. The test results are now reported as a percent change from the control and can be compared easily between tests and among materials. An individual can now distinguish among materials that have "just failed," "just passed," failed by a lot, or passed easily.
ANSI is also discussing the implication of recent research conducted by Mark McCormick-Goodhart of the Conservation Analytical Lab at the Smithsonian. This research, presented at both PMG/AIC meetings held in 1992 and 1993, has investigated the effect of cold temperatures and low relative humidity storage on photographs using computer modeling techniques in addition to "real life" testing.
McCormick-Goodhart's research revealed that lowering the storage temperature did not cause stress in photographs (a Cibachrome color print material was used as the test "model"), but that lowering the relative humidity did cause stress--the gelatin binder contracted, causing curl, and existing cracks became worse. The work confirms Connie McCabe's research on the effect of low humidity on glass plate negatives. Both researchers found that low humidity was most detrimental when the photographs had existing damage such as cracks or flaking, both of which are common in holdings of older materials. (ANSI IT9.11-1991 Storage of Safety Film recommends storage conditions for new B/W film of permanent value, at no more than 70°F and between 20% and 30% RH to retard film base deterioration of acetate film. Conservators and collection managers have expressed concern that this RH could be too low for vintage materials and too expensive to achieve.)
McCormick-Goodhart recommends lowering the temperature (preferably below freezing) of a storage area, while maintaining an RH closer to the user environment (45%-50%) in order to minimize stress and maximize chemical stability. Collection managers may find that this is just as costly as maintaining extremely low RH. An appropriate combination of cool temperature (40°-65°F) and moderately low RH (35%-45% RH) may provide a reasonable cost/benefit ratio of good storage conditions to maximize the preservation of one's black-and-white film holdings at an affordable cost.
AIC=American Institute for Conservation
ANSI=American National Standards Institute
IPI=Image Permanence Institute
MAPS=MicrogrAphic Preservation Service
NARA=National Archives and Records Administration
NEH=National Endowment for the Humanities
PAT=Photographic Activity Test
PMG=Photographic Materials Group
Note: the addresses of AIC, ANSI, IPI, NARA, and NEH are given in the list of "Useful Addresses" sent to all subscribers.