45th Annual Meeting – Photographic Material Session, May 31st, “Providing Access to “Overprotected” Color Slides” by Diana L. Diaz-Cañas

Photograph conservator Diana Diaz introduced her presentation as a study case which deals with “overwhelming protection” of photographic materials.

The project started in 2006 when the Harry Ransom Center acquired the photographer Arnold Newman’s archives, including various photographic and other materials, such as photographic albums, sketch books, documentation of many projects… and color transparencies.

More precisely, a corpus of 35 mm Kodak Kodachrome color slides in plastic mounts was found. The slides were wrapped together with sealing tapes, forming in 16 sets. The tapes displayed, on the edge of each pack, handwritten inscriptions indicating the dates and subjects of the photographs. The dates inscribed on the tape enabled to date each project, the whole collection ranging from 1954 to 1972. Diana Diaz showed several examples of the images, like one taken for a project shot in Spain in 1970 for Holiday Magazine.

These slides series are of interest as they inform on the photographer’s working methods. For instance, they showed different cropping, compositions, and exposures experimented within each series. One can see how Newman would play with lights and colors and produce variations of the same images, among which he would then make his final selection for the publication. Diaz then listed all the assignments projects covered in the slides, shot in various places (Spain, Canada, California…) for different magazines, such as Harper’s Bazaar or Life.

However, when the slides were found, the images were still inaccessible since after the removal of the tape applied on one edge displaying the inscriptions, another white tape underneath maintained the stacks of slides together. Three types of tape were identified among the 16 sets:

  1. a masking tape;
  2. a discolored white tape;
  3. a white tape still tacky.

The conservation treatment needed then was difficult to engage because the tapes were in contact, not only with the slides mounts, but also with the films themselves – on both the image and support sides.

Therefore, to remove the tape carrier, Diaz logically proceeded by types of tape.

  • The white tape still tacky was removed mechanically with a spatula, without any adhesive residue left at the end of the treatment.
  • The masking tape was strongly adhered and did require a heated spatula combined with the use of solvents.
  • The discolored white tape was removed with the help of water vapor.

After all the carriers were removed, Diaz evaluated the materials and condition of the residual adhesives in order to determine which solvent to use. She referred to Smith et. al.’s paper1, which not only presents the history of pressure sensitive tape and their ageing properties, but also appropriate solvents and suitable methods of application for their removal. Thus, Diaz used naphtha (a mix of hydrocarbons) to successfully remove the rubber-based adhesive, and ethanol for the oily adhesives. The solvents were applied gently with a cotton swab in a circulation motion and in one direction to minimize the scratches and increase the efficiency.

The photographic documentation under Ultra-Violet illumination allowed to assess the removal of all the adhesives. Finally, the slides were individually rehoused in conservation materials.

Although this treatment was successful, several questions are being raised: Are there remaining solvents residues in the photographic materials at the end of the treatment? Has the surface been scratched? Indeed, the topic of the effect of solvents on color transparencies, in particular regarding the innocuousness for the photographic materials, would require further research to help photograph conservator to choose a suitable treatment.


1 Bibliographic reference: Merrily A. Smith, Norvell M. M. Jones, Susan L. Page, & Marian Peck Dirda. “Pressure-Sensitive Tape and Techniques for its Removal From Paper”
JAIC 1984, Volume 23, Number 2, Article 3 (pp. 101 to 113

44th Annual Meeting – Photographic Materials Session, May 16, “Photochromatic Images of Edmond Becquerel: Where do the colours come from? Tracks in the understanding of the origin of their colours.” by Dr. Marie-Angélique Languille, Edouard de Saint-Ours, Jean-Marc Frigerio, and Christine Andraud

Edouard de Saint-Ours clearly described the fascinating work he and his colleagues have done to identify the source of the colors in one of the earliest color photographic processes. In 1848 Edmond Becquerel successfully produced a color photographic image, but himself was unable to identify the cause of the colors. The discovery of several of his early plates in the archives at the National Museum of Natural History in Paris sparked Edouard and his colleagues’ interest in Becquerel’s process and the source of his colors.
Edouard began by explaining the two known ways in which color can be produced in photography: through the use of colorants, or through the production of interference colors. It was assumed that Becquerel had been relying on one of these two types of color, and the research team focused on methods of analysis that would identify either of these two methods of producing color.
Becquerel’s photochromatic images were made by dispersing sunlight through a prism for several hours, exposing the plate in camera to form a direct positive. The images were not fixed, and will fade if exposed to light. In order to understand the physical and chemical composition of the Becquerel plate, Edouard and his colleagues replicated the technique themselves. To make a photochromatic image a silver plate was polished and cleaned, and sensitized by immersion in copper chloride, or by hydrolysis in a bath of hydrochloric acid. The latter is referred to as an electrochemically sensitized plate. Once sensitized, the plate takes on a red-brown hue. In the replication of the process the plates were exposed to a Xenon lamp with colored filters, and the colors produced on the plate corresponded to the color of the light.
Once they had replicated the technique, they set about studying their sample plates in order to identify the cause of the colors they had produced. SEM analysis and cross-sectional analysis showed that there were no surface or structural differences between the different colors. Although this suggested against interferential colors, it did not rule out the possibility entirely.
SEM-EDX offered the researchers more information about the chemical composition of the different colors, but also indicated no difference between the green and red colors on the sample plate. Both were almost entirely comprised of silver chloride. However, Edouard mentioned the very interesting possibility that very small variations in the proportion of silver could cause different sizes of silver nanoparticles to form on the plates. In this scenario, a different size of nanoparticle would form from each color of light, and the color of the silver nanoparticles would vary depending on their size.
From this hypothesis, the researchers performed spectroscopic analysis of the colored surfaces, a technique which can detect the chemical state of an element. However, this analysis showed only oxidized silver on all colors, with no indication of difference between colors, or the presence of metallic silver. Again, this suggests against the presence of silver nanoparticles, but does not definitively rule out that possibility.
Although the project has not returned any definitive results, the research is ongoing. In the meantime, the work has cast light on the complexity of Becquerel’s early process, and the intriguing questions still presented by early color photography.

44th Annual Meeting – Photographic Materials Session, May 16, “Understanding Temperature and Moisture Equilibration: A Path towards Sustainable Strategies for Museum, Library and Archives Collections,” by Jean-Louis Bigourdan

Preventive conservation is becoming an increasingly important part of our work as conservators, but it often seems that many important questions about environmental control have yet to be answered. Questions such as to what degree are fluctuations of temperature and RH humidity damaging to collections, and are they more or less damaging than strictly maintained but not ideal conditions?
Jean-Louis Bigourdan addressed some of these uncertainties in his talk on temperature and moisture equilibration in storage spaces containing significant quantities of hygroscopic materials. He focused on reconciling the need for climate-controlled storage with the quest for sustainability and the pressure of budgetary limitations. His introduction was reassuring: the current thinking on storage climate is that relatively stable low temperatures are desirable (“cool storage”), but there is little benefit to maintaining a perfectly stable climate (i.e. without fluctuations). Rather, a certain degree of cycling is acceptable, so long as the shifts are not extreme.
Following from this fact, Jean-Louis presented the concept of “dynamic management” of HVAC systems. Dynamic management entails shutting down the HVAC for short periods, such as overnight, and adjusting climate set points seasonally. This would save on energy, and thus reduce the environmental impact and cost of operating such systems. Of course, we as conservators are immediately concerned with the effect on collections materials during such shutdowns: How extreme are the fluctuations in temperature and RH resulting from periodic shutdowns of the HVAC?
This is the questions Jean-Louis attempted to answer through two phases of testing. He was particularly focused on the possibility that collections containing large quantities of cellulosic and/or hygroscopic materials might buffer against large or sudden shifts in temperature and RH. Jean-Louis undertook two phases of testing to understand the extent of the self-buffering capabilities of such materials. The first round of testing was conducted in the laboratory, and the second in library and archive collections storage rooms.
In his laboratory tests he exposed different types of materials to large fluctuations in temperature and RH. The materials included things like closed books, matted photographs and drawings in stacks, and stacks of unmatted photographs. He also tested the effects on these materials when they were placed inside cellulosic microenvironments, such as archive storage boxes, measuring the temperature and RH at the surface of objects, and at their cores. His results indicated that the RH at the core of books or stacks of cellulosic material does not change as rapidly as the exterior environment. Temperature equilibration occurred over a period of hours, and moisture equilibration occurred over the course of weeks or even months. Microenvironments increased the time to equilibration, mostly by controlling diffusion of air.
Another useful result of this laboratory experimentation was that it demonstrated that the moisture content of paper-based and film collections was more affected by environmental temperature than by environmental RH. In other words, at the same exterior RH, the moisture content of the collections object was lower at higher exterior temperatures. The laboratory testing therefore suggested that storage spaces with significant quantitates of hygroscopic materials will be buffered against large changes in RH and temperature due to moisture exchange with the collections materials.
Jean-Louis found that field testing in collections storage spaces returned many of the same results as his laboratory tests. 6-8 hour shutdowns of HVAC systems had little impact on environmental RH, and many of the systems they examined were already following seasonal climate cycles without causing dramatic shifts in the temperature or RH of storage environments. He encouraged conservators to take their collections materials into account when evaluating the buffering capacity of their storage environments.
I was very encouraged by these findings, although I have some remaining questions about the potential effects on collections materials. How much moisture is being exchanged with collections items in such a scenario? Is it enough to cause dimensional change in hygroscopic materials, especially on exterior surfaces, and will that contribute to more rapid deterioration in the long term? Regardless, I was happy to be prompted to remember that collections materials are an active part of the storage environment, not an unreactive occupant of it.
The talk wrapped up with Jean-Louis raising a few areas of further research. He hypothesized that changes in storage climate which are achieved through a series of small but sharp changes would result in slower moisture equilibration between environment and collections than would a change made on a continuous gradient. He also raised the possibility of predicting the internal moisture fluctuations of collections materials using their known hygroscopic half-lives. Both of these areas of research could be extremely helpful to conservators attempting any dynamic management of their climate control systems.
A particularly thoughtful question by an audience member provided the opportunity for more climate control wisdom. A Boston-area conservator of library and archive collections wondered whether it made sense to use dew point as the set point on HVAC systems in the winter to save money on heating costs, but during the summer to use RH as the set point to insure against mold growth. Jean-Louis felt this would be an unnecessarily complicated method of control, but offered a general rule for the storage of hygroscopic collections. He suggested thinking of lower temperatures as the primary goal, and of RH as important to maintain within a broader range. Lower temperature slow degradation reactions inherent to such materials, and so generally lower is better. However, RH need only be high enough so as not to embrittle material, but low enough to prevent mold growth. Essentially he suggested that if your RH and temperature are too high, you are better off reducing temperature slightly, which will slow degradation reactions, and as a side-effect your collections may absorb a small amount of moisture, thereby lowering the RH in the building environment.
Jean-Louis’s talk left me intrigued and excited about the possibility of taking advantage of hygroscopic collections materials to provide a more stable and sustainable storage environment.

43rd Annual Meeting – Photographic Materials, May 14, "Object:Photo – A Presentation of Deep Data from the Thomas Walther Collection Project at The Museum of Modern Art" by Lee Ann Daffner

Object:Photo | MoMA
MoMA Object:Photo Home Page

After The Museum of Modern Art acquired the Thomas Walther Collection, a rare collection of fine art photographs made primarily between World War I and World War II, MoMA was awarded a generous grant from The Andrew W. Mellon Foundation to conduct a comprehensive study of the collection.  The survey culminated in a symposium, publication, exhibition, and interactive website sharing the data collected during the four-year endeavor.
During the Photographic Materials Group Session, Lee Ann Daffner focused on the data collected during the survey and the way in which the interactive Object:Photo website uses the analysis to build relationships between photographs by geography, exhibitions, artistic schools and spheres of influence.  The site is designed to encourage organic browsing by the user by highlighting action links in red, a bright contrast to the black and white theme reminiscent of the silver gelatin photographs which largely make up the collection. Before reading further about the project, I recommend spending time exploring the site, available at http://www.moma.org/objectphoto. It’s rich with information, yet feels more like wandering through an exhibition than browsing a website full of technical data.
Not only does Object:Photo make the Thomas Walther Collection images available online, it also highlights technical and historical data of each image. High resolution images of the front and back of each photograph, specular images highlighting the surface texture and sheen, detailed description of the photographic paper and technical analysis, as well as essays, exhibitions, and related articles are included to enrich each photograph in the collection.
In collaboration with Paul Messier, polynomial texture map (PTM) and microraking images of paper texture were created. This setup and process is illustrated and described beautifully in the Materials section of the site, and Mr. Messier outlined similar protocols for analysis later in the conference during his presentation titled “Revealing Affinities across Collections through the Language of the Photographic Print.”
Linking artwork with technical analysis, Object:Photo places each photograph in context in comparison to the others an artistic expression of the world between the two world wars. The presentation of the material is geared toward universal understanding by both scholars and museum visitors because “it was important to share all the data,” according to Ms. Daffner. MoMA’s data on x-ray fluorescence (XRF) analysis, fiber analysis and paper thickness is available for download in Microsoft Excel file format.
While this website pertains only to the Thomas Walther Collection and the research conducted during the four-year survey, the Object:Photo project is an excellent example to other institutions who may conduct similar surveys in the future.  Ms. Daffner and MoMA should be proud to encourage the development of industry standards and research protocols with Object:Photo. Please take the opportunity to explore MoMA’s Object:Photo site at http://www.moma.org/objectphoto.

AIC 43rd Annual Meeting – A Glimpse from the Dawn of Photography: Investigation and Stabilization of an Early Daguerreotype from 1839 at the Peabody Essex Museum. Elena Bulat and Kathryn Carey

For this presentation Kathryn Carey, paper conservator at the Peabody Essex Museum (Massachusetts), introduced the project and the museum. The Peabody Essex received an early daguerreotype dated 1839 from a donor in 1858. The image is of Pont Neuf in Paris, and the plate is tentatively attributed to Vincent Chevalier, or Daguerre himself. The daguerreotype was “rediscovered” in 2008 and Elena Bulat, photograph conservator at Harvard University’s Weissman Preservation Center, was contracted to perform analysis and treatment. The daguerreotype was housed in the European style with a paper passe-partout and framed. Elena’s work consisted of opening the package, digitally imaging the plate, performing XRF on the plate and FTIR on the glues, fiber analysis of the papers, observation and imaging under UV radiation, removal of superficial dust from the plate with a manual air blower, replacement of the old passe-partout  and cover glass with new but similar materials, and rebinding. XRF revealed low levels of Hg and no Au. S was found in tarnish areas, and no Cl was found. These results in conjunction with observation under UV confirm the identification of this plate as an early 19th century daguerreotype that was cleaned. FTIR revealed beeswax, and fiber analysis found bast and cotton fibers in the paper components. The new housing for the plate consisted of a backing piece of borosilicate glass, a window mat of borosilicate glass, and a new cover glass (also borosilicate). The plate was secured between these layers with a mylar Z-tray. Elena recommended the plate not be exhibited as it was not stabilized by gold toning.
Elena described her experience speaking with a reporter from the Boston Globe regarding this project, and how he had difficulty grasping the concept that “treatment” does not necessarily mean intervention. This rang true for me, and I imagine for many other conservators in the audience. You can read the article here: http://www.boston.com/ae/theater_arts/articles/2010/06/27/a_glimpse_from_dawn_of_photography/

PMG Winter Meeting – “Photographic Paper XYZ: de facto standard sizes for silver gelatin prints” by Jennifer McGlinchey Sexton, Feb. 20

Jennifer McGlinchey started her impressive talk with an explanation of the history of lists of photographic paper sizes. She stated that there were no available references that have lists of ‘standard’ sizes. In fact, the lists of sizes they were able to find were very small, and also corresponded to very specific time periods. Further research suggests that these sizes were not considered standard and were certainly not inclusive of all sizes used. Rather than identify ‘standard’ sizes, she identified ‘common’ sizes by the criteria that they appear in five or more of the references. These she concluded were ‘de facto standard sizes.’ For the study, McGlinchey used Paul Messier’s extraordinary paper collection which consists of over 5,000 samples of silver gelatin photographic paper, as well as 9 manufacturer’s sample books and pricelists and 6 encyclopedias: http://www.paulmessier.com/
The use of English-language publications from a few geographic locations (US and Europe) may have been limiting, but in fact, there are very few references from other geographical areas. Concluding that there were common rather than standard sizes is not to say that there were no attempts to standardize paper sizes, but the attempts were never very successful. The result of the study was that she identified over 200 distinct sizes, just over half of which occurred only once. She identified 32 de facto standard sizes. Many of the sizes considered common now in the USA, such as 4×6 and 5×7 inches, are included in that list, but many sizes which are no longer manufactured are also on that list. This includes smaller sizes like 2.5 x 2.5 inch, which were much more common in early days of gelatin silver printing. She mentioned that the measurements for papers grouped together as the same size allowed for a difference of +/1 5 mm along each dimension, to account for natural expansion/contraction, ferrotyping, and so on, which could account for small dimensional changes. As part of the research they also evaluated common thicknesses of silver gelatin paper, and found three de facto standards. The most common was ‘single weight,’ followed by ‘double,’ and finally ‘medium.’ Double weight papers fall above 0.25 mm, medium weight papers under 0.25 and single weight papers under 0.2 mm. The double weight paper started get thicker in the 1930s until the 1950s and then got thinner again, so manufacturers changed the thicknesses over time but not the terminology. It was also found that five common aspect ratios occurred in 88% of the de facto standard sizes. This implies that scaling relationships were a factor for determining silver gelatin DOP paper sizes. Characterization by aspect ratio not only simplifies the dimensional diversity of silver gelatin paper by emphasizing their scaling relationships, but also highlights their relationship with other media. For example, 6:5 is common mainly with plate sizes, 5:4 is the aspect ratio of many large format films. 4:3 is the first motion picture aspect ratio and 8:5 is the golden ratio.
The measurements and other data were recorded in spreadsheets (the full results were published in JAIC, Volume 53, Issue 4 (November, 2014), pp. 219-235). It led to the conclusion that there is no easy answer to these questions. No system of standard paper sizes was successfully put in place for photographic papers. Additionally, available sizes varied widely over time and across geographic boundaries.
This research can be utilized in identification of artist’s methods and paper preferences. One useful application is to study photograms. This technique was used to great effect by Man Ray and Laszlo Maholy-Nagy, contemporaries working in France and Germany respectively. Of course, each print is unique, because it would be difficult to replicate the exact condition since no negative has been used. Of a selection of 163 prints by Man Ray dating from 1920 to 1940, there were 88 photograms and 75 traditional prints from negatives. Compared with the de facto standard sizes identified by this research, the dimensions of 39 Man Ray photograms (roughly 44%) correspond to de facto paper sizes. From 75 prints from negatives, only 25 (33%) correspond to the de facto paper sizes. This survey shows that Man Ray most likely trimmed his photographs from negatives, but didn’t trim his photograms. Averaging about 3.5 mm thickness, the photograms fall into the category of double weight papers.
Man Ray’s process contrasted with the working practices of Laszlo Maholy-Nagy. Print dimensions and estimated thickness for 216 prints by Maholy-Nagy made in Germany between 1922 and 1928 were collected from the catalogue raisonne of his photograms. Of these photograms, 216 or about 89% correspond to the de facto standard sizes identified by this research. The majority of the prints made from negatives were printed on two sizes of paper, 18 x 24 cm and 13 x 18 cm, both de facto standard sizes. This shows that Moholy-Nagy used full sheets of paper for his photograms and didn’t trim them down. The catalogue raisonne describes the thickness measurements of many Moholy-Nagy photograms as single weight or double weight. According to these descriptions Moholy-Nagy used the single weight or double weight papers in equal frequencies and sometimes used both in the same series.
Understanding the de facto standard sizes provides a useful point of comparison of these two artists. Differences in their methods can be due to a variety of factors. Moholy-Nagy was known for his scientific approach to photography, as a record of the interaction between light and physical object composed within the border of the paper. His photograms were complete upon processing. In contrast, Man Ray was more acutely engaged in producing highly refined settings of expression; attention to detail and subtle manipulation apply to all aspects of Man Ray’s photography as evidenced by his skilled practices in retouching and using carefully proportioned mounts.
In summary, there really were a lot photographic paper sizes available, particularly in middle of the 20th century, when these papers were extremely popular. While there are some de facto standard sizes and thicknesses, silver gelatin papers were made in numerous sizes and the majority of paper sizes listed in the references occurred only once.

PMG Winter Meeting – "New Photo Histories in West Africa" by Erin Haney, Feb. 21

This was the final session of the 2015 PMG Winter Meeting.  Speaker Erin Haney is an art historian and co-founder/co-director of Resolution, which hosted the 2014 “3PA” workshop in Benin. During the Q&A afterward, one conservator remarked that her talk “reminds us why we do what we do.” That couldn’t be more true. She provided an exciting glimpse of family and private photograph collections in West Africa that have not been widely seen nor studied. The stewards of important West African photography collections have recently started to come together to explore strategies for their preservation as well as raising their visibility worldwide.
She began by saying that West Africa has valuable historic photographs that won’t come up on Google searches. The reason is simply that these photographs tend to be dispersed widely in private and family collections. There are very few cultural institutions, archives and museums that have enjoyed stability from the colonial era to the present day. Some institutions have lost all or part of their photographic collections in times of political upheaval. Instead, it is primarily families and private owners who have safeguarded that region’s photographic heritage.
Haney showed just a few examples that reflect the diversity of images that can be found in these collections. These include photographs made during the colonial period, the images made by the great, early studios (often now in family collections of their descendants), domestic portraits, group portraits, and events of social and political importance. There are images of the social elite and the wealthy, showing a materially rich and cosmopolitan West Africa that is seldom seen, and a history that is seldom taught. She showed a daguerreotype by Augustus Washington, who went to Liberia from the US and made daguerreotypes in cities all along the West African coast. There were photographs made by the Lutterodt family, which established a far-reaching network of family photography studios that operated from the 1870’s to the 1940’s. There were British colonial scenes, portraits by early French-run studios, portraits of West African women and their Bordeaux trader husbands, and debut portraits–young women dressed in the finest cloth, showing their readiness for marriage. More recent images included Gold Coast soldiers, independence movements, city skylines and infrastructure, and prominent political figures. These are but a few of the many treasures in these collections, spanning the 19th and 20th centuries. There is an extraordinary variety of subjects and photographic traditions.
She showed how photographs were made and remade in order to improve them and preserve them. Some photographs took on new meaning as memorial objects when the sitter passed away. These could be marked with crosses, mounted, and/or captioned by loved ones. Other photographs that had condition issues over time might be heavily overpainted to refresh them. In one case, a painting of a Dutch ancestor was remade by photographing it, in order to present it alongside a group of other family portrait photographs. The original image was not sacred. To study these collections, one has to understand how the images functioned when they were made and how they continue to function. Theirs is an iterative practice of artistry, which must inform preservation and conservation decision-making.
Of grave concern today is that these collections are at risk when the custodians feel they must sell or dispose of them to reclaim the valuable space they occupy in a private home, or generate much-needed income. Resolution communicates the importance of photographic cultural heritage to people in West Africa and around the world. The Benin workshop provided participants with the skills to document and manage their collections, while networking with others in the region working toward the same goals. The workshop involved nine countries in Francophone West Africa and is actively building partnerships and capacity to make a case for the ongoing support of photographic collections. There is a growing recognition of their critical importance for national identity, education and research. It was an inspiring end to this PMG Winter Meeting.

PMG Winter Meeting – "Cataloging Is Preservation: An Emerging Consideration in Photograph Conservation Programs" by Robert Burton, Feb. 20

“Cataloging Is Preservation: An Emerging Consideration in Photograph Conservation Programs” was the first talk of the Biannual PMG Winter Meeting in Cambridge, MA, February 20-21, 2015.  Speaker Robert Burton began with a quote from his mentor Sally Buchanan, who stated, “Cataloging is preservation.” Burton went on to show how that is no overstatement. In a sense, the goal of all conservation is to preserve materials to enable continued access to them, and there is a direct relationship between cataloging and access. Descriptive records in prescribed formats, organized under controlled headings, make photographs discoverable. This in turn sparks research interest, helps institutions identify preservation priorities, and even helps them organize storage more efficiently. Burton showed that cataloging is the foundation of a comprehensive view of collections management and preventive conservation.
A good record should answer the questions: who, what, when, where, why, and how? It gives an institution administrative and intellectual control over its photographic materials. Whereas books and other text-rich objects are more self-identifying, photographs require additional data to be contextualized, and collecting this data requires a cataloger with the appropriate training.  A cataloger might be the first person to go through a photograph collection, and that person should possess visual literacy, an understanding of photographic processes, an ability to carry out basic preventive measures such as rehousing, and be able to bring objects in need of special care to the attention of conservators. Because different institutions have diverse approaches (different databases, digital asset management systems, missions, and constituents), catalogers must understand and apply data value standards to bring some consistency to searches for terms such as artists’ names, geographic place names, and so on. (Burton mentioned the Getty Art and Architecture Thesaurus and the Name Authority File from the Library of Congress as examples.)
Recent advances in digital recordkeeping and digital imaging have reduced the administrative burden of cataloging and have also reduced the need for over-handling photographic materials, which can result in handling damage. There are new technologies on the horizon that will help with cataloging, such as automatic captioning of newly created images, or giving photographers a way to record voice annotations as additional metadata. Nevertheless, catalogers will need to find a way to enter this information so it can be searched.
Without knowing its holdings, instititions will not be able to adequately value or safeguard their materials, nor will they be able to care for them. Uncataloged items are essentially invisible: vulnerable to loss, their condition and value unknown.
Burton acknowledged that few library school programs provide students with the opportunity to study photographic materials specifically.  He urged this audience to view cataloging as a preventive conservation method on par with environmental monitoring, housings, and the like. He traced the development of this thinking to the 2002 Mellon survey at Harvard, which in turn became the model for the Weissman Preservation Center’s Photograph Conservation Program, and then FAIC’s Hermitage Photograph Conservation Initiative. These surveys show that, by coordinating conservation, cataloging, and digital imaging, photograph collections are more accessible and in better condition. This positive trend should continue as more institutions adopt Susan Buchanan’s mindset: “Cataloging is preservation.”