The most common types of photographic prints found in cultural institutions are cased photographs, albumen prints, silver gelatin prints, and modern color photographs. These may be stored with documents in files, in boxes or albums, or even loose in drawers.
As you have seen in this session, different types of photographic processes have specific vulnerabilities. However, there are some major categories of damage to photographs that you may observe within your collection. As with paper documents, photographic prints are subject to physical damage such as tears, creases, dog-eared corners, and mold or insect attack. Special concerns for photographs are abrasion and scratching of emulsions (binders), cracking emulsions, emulsions that are peeling away from the support layer, and indentations or staining caused by writing on the back of photographs.
Chemical damage to photographs may manifest itself in black and white images through fading of the image, loss of image detail, yellowing of the image, silver mirroring of shadow areas of the image, and/or staining. For color prints, color change and fading are the primary results of deterioration.
Rolled photographs are often found in collections. As with documents, these should not be unrolled if it seems this may cause damage; a conservator should be consulted. Photographs mounted on acidic boards are also common (these are frequently albumen prints, which tend to curl up if not mounted). There is often physical damage to the board and chemical damage to the photograph.
Photograph albums pose additional problems, since the albums themselves may damage the photographs. Many older albums have acidic pages that can accelerate photograph deterioration. Adhesives used to attach photographs often cause staining and sometimes fail, leaving the photograph unattached. Modern "magnetic" albums in fact use adhesive to hold the photograph to the page; this adhesive darkens and stains photographs over time. Modern albums with plastic pages made from polyvinyl chloride (PVC) also accelerate photograph deterioration. Polyester, polypropylene, and polyethylene are the only acceptable plastics for photo album pages.
You have explored the mechanisms of deterioration for film-based and electronic media and briefly examined the role of external factors in collection deterioration. In this section you will begin to relate this information to your own collections.
IMPORTANT: This examination of your collections is not meant to serve as a formal collection condition survey, but it will assist you in determining which materials need further attention. You may decide that one or more collection condition surveys are required for specific subsets of your film-based or electronic materials (e.g., reel-to-reel tapes, photographic negatives, motion picture films). This type of inspection most often takes the form of an item-by-item survey by a conservator with detailed knowledge of that particular type of collection.
Photographic negatives and transparencies in your collection may include glass plate negatives, lantern slides, autochromes, black and white film negatives, color film negatives, and color slides. Older film negatives may be on nitrate film, while newer ones are likely on acetate or polyester film.
Types of physical damage you may observe include broken or cracked glass plates or covering glass, broken tape seals on lantern slides or autochromes, and cracking or flaking of glass plate emulsions. Mold growth may also be a problem. Deteriorated color negatives and slides may show evidence of fading or color change (dye shifts).
Evidence of chemical damage due to the deterioration of nitrate film may include yellowing, stickiness, and a nitric acid odor. Nitrate films that are in an advanced state of deterioration will be soft and may adhere to adjacent films or enclosures, or they may have partially disintegrated into a brown powder. Evidence of chemical deterioration of acetate film due to vinegar syndrome may include a vinegar odor, curling, or staining. Advanced deterioration will manifest itself through bubbles on the film and separation of the emulsion from the base. Nitrate or acetate film may sometimes be identified by edge printing (it will say NITRATE or SAFETY).
Photographic negatives and transparencies were manufactured in a wide variety of sizes. EdinPhoto's helpful Sizes of Photographs website explores a variety of photographic formats, and the Chart of Plates, Negatives, and Prints provides a scaled overview of common sizes.
Various types of scrapbooks are found in cultural collections. News clipping scrapbooks are common, as are personal scrapbooks that contain a variety of materials, including documents, photographs, pamphlets, and pressed flowers.
Scrapbooks, being composite objects, exhibit various problems common to documents, bound volumes, and photographic materials. Their pages may be brittle and weak, photographs may be faded and stained, news clippings may be yellowed, items may have become detached from the pages due to adhesive failure, the pages may have been stained by adhesives, and the bindings may be broken or otherwise damaged. Scrapbooks are often good candidates for reformatting, which is discussed further in Session 7: Reformatting and Digitization.