By HELEN DALRYMPLE
The Packard Campus will provide the Library with ample cool, dry storage space and the latest tools and technologies with which to extract sounds and images from disintegrating media and to preserve them in digital formats that can be served easily to generations of users.
The problems inherent in preserving and providing access to such historical and varied collection are legion. Technological obsolescence is a major problem, whether the recording medium is an 1888 wax cylinder, a lacquered 78-rpm record from the 1940s, a steel wire from the early 1950s, an eight-track audio tape from 1964 or a Betamax video from 1975. A single recording medium such as magnetic tape poses a variety of information-access problems. Available in a variety of widths, lengths and recording speeds, tapes could be recorded and played on a variety of reel-to-reel machines and on cassette players in assorted sizes. Recording-head configurations varied.
The recording medium itself deteriorates over time. Steel wire and tape become tangled and can break. Lacquer coatings can peel off old records, the iron oxide of magnetic tape disintegrates, and some tapes become so sticky that they have to be baked for several hours before they can be unrolled.
Motion picture films have their own problems. Film consists of a thin plastic base coated with a layer of gelatin emulsion, which contains the image. The image is made either from silver particles, for black-and-white film, or color dyes. Until 1951, early motion picture film was made with a cellulose nitrate base, which is highly flammable and subject to severe deterioration unless it is properly stored. Motion pictures made on nitrate film stock are now being transferred to and preserved on polyester-based film stock at the Library's laboratory in Dayton, a process that will continue at Culpeper.
The initial preservation efforts of the Library (and other archives as well) involved the use of "safety" film, which is made with a cellulose triacetate base and is not combustible. However, it was discovered in the late 1970s that acetate film would also deteriorate, resulting in a condition which came to be known as "vinegar syndrome." This occurs when the base plastic reacts with water in the air to form acetic acid, which produces a vinegar odor. Film so affected shrinks, starts to "wave" so that it will not lie flat, and develops a white powder on the edge. The emulsion may crack, fragmenting the image, and then flake off the plastic base. Once polyester-based films were perfected and readily available in the early to mid-1990s, the Library's film preservation laboratory began using them for most preservation projects.
Films are also subject to color-fading over time, to mold if improperly stored, and to mechanical damage from frequent projection or contact with dirt or other contaminants.
Early Technicolor films did not fade. Then, in 1954 Eastman Kodak introduced Eastman Color, which is subject to fading unless the film is preserved in cold vaults, like those at the Packard Campus, which feature a steady temperature of 25 degrees to 45 degrees Fahrenheit and relative humidity of 30 percent.