What Is a Bound Collection of Photos and Documents

Preservation worked with digital conversion experts to select and customize the scanning equipment used to digitize the library`s collections. When library holdings are digitized by contractors, Preservation reviews and approves the equipment, always taking into account the format and character of the objects to be digitized, in order to minimize the risk of damage to the collections. Once the collection has been inventoried, evaluated, catalogued and organized according to library and archive standards, certain photographic documents (such as cellulose nitrate and cellulose acetate film-based materials, as well as photographs of chromogenic dyes) should be housed and stored separately if possible. By isolating these photos, these items can be stored in colder, drier environments that maximize their lifespan. In addition, the separation of some photographic materials, such as. B the deterioration of film-based materials, reduces the risk of damage caused by acid degassing, which can damage other photos stored nearby. Finally, fire safety regulations may require separate storage of cellulose nitrate materials. (NFPA 40) However, the nature of many collections does not allow for the separation of different materials, and a compromise often has to be made between the conflicting needs of the photographs in the collection. High quality reproductions should be made for items that are too damaged to be handled without damage. Once a damaged original has been duplicated or reproduced, it can be removed from service for researchers. Increasingly, digitization projects are making these substitutes available.

Electrostatic printing Electrostatic technology has been used in office photocopiers since 1959. Adding a laser to the system makes it possible to print digital information. Over the past twenty years, electrostatic color systems have become commonplace. Increasingly, computer printers and photocopiers with electrostatic technology are being used to create not only text documents, but also black and white and color photos as digital file output. In these systems, toner containing resin and pigments is fused with heat to form paper. At this point, these materials are generally of lower image quality than inkjet and color sublimation prints and are less commonly used for the production of works of art. However, these systems are less sensitive to water and pollutants due to the type of pigments and resins that can be used. Since some of the pigments in these systems are somewhat unstable, caution is advised in exposure. In addition, many office papers are of poor quality and can fade with prolonged exposure to light.

Digitization technicians at the Library of Congress are trained by preservation specialists in the basics of careful handling of library materials and the safe support of objects on scanning devices. Conservation staff teach with non-related samples of bound documents, flat documents, graphic prints, manuscripts, atlases, photographs and photo albums to demonstrate the damage that can occur with fragile library documents during scanning. The ideal RH for storing a mixed collection of historical photo prints, slides and negatives is a set point between 30% and 50%, without going through more than +/- 5% per day. If only the photos are stored in a certain area, 30-40% RH is preferable. When photos are stored with paper, parchment or leather, it may be necessary to maintain 40-50% RH to avoid unwanted stress on non-photographic materials. However, some materials, such as negative films and transparent films (nitrate plastic and acetate) and some historical glass plate negatives, will continue to deteriorate at 40-50% RH. The deterioration of acetate and nitrate is highly dependent on RH, even at moderate levels of 40-50%. Recent changes in international organization for standardization (ISO) specifications recommend several different climate zones that can achieve the same projected life expectancy for photographs based on film and chomogen dyes. These climate options are based on the concept that temperature and relative humidity have a synergistic effect on each other – in some areas, a lower temperature can compensate for higher relative humidity and vice versa. For example, the RH range at cool temperatures (7°C) is 20-30%, while colder temperatures allow for a wider range between 20-40% at -3°C or even 20-50% at -10°C. (ISO 18911) Recent research suggests that historical nitrate films also benefit from the same storage conditions. (Reilly 1993) Glass plate negatives should be kept at 30-40% RH to minimize decomposition and flaking of the glass.

(ISO 18918) Inkjet prints, especially those from the early and mid-1990s, can be particularly sensitive to high humidity. In some processes, significant damage can occur due to humidity of more than 80%. As with other photos, a relative humidity of more than 50% should be avoided when storing inkjet prints. Cellulose Nitrate Negative Cellulose Nitrate Film was produced in the United States between 1889 and 1951. It was produced in other countries until the 1960s. Eastman Kodak was the first company to successfully produce nitrate films in series, but it was also produced by other companies around the world. Cellulose nitrate is flammable and must be stored, transported and disposed of in accordance with applicable regulations and regulations. (NFPA 40) The nitrate film is inherently unstable and becomes acidic, sticky and brittle with age. Cellulose nitrate gradually deteriorates, starting with a degradation of the plastic support with cellulose nitrate. When nitrate deteriorates, it poses a threat to other types of photographs stored in the area by emitting nitrogen oxides that attack the silver image, the gelatin binder and finally the support base of other papers and films. Nitrated materials should be identified, accurately duplicated if possible, housed in buffered paper enclosures (never plastic) and stored by other collection materials in a well-ventilated room. (Eastman Kodak 1998.) All nitrate films should be checked regularly for signs of deterioration.

Cellulose nitrate in poor condition can ignite at temperatures up to 41 ° C. Fire safety regulations require nitrate-based materials to be stored separately in fireproof cabinets, safes or off-site. Storage at low temperatures and low relative humidity significantly slows down the deterioration of the nitrate film. The possibilities for digitizing linked materials are multiple and what is effective for one collection may not be suitable for another. Additional research may be required to find the exact scanning method that best suits your collection. However, these four points are an excellent starting point for further investigation. The risk of damage to materials is increased if researchers and personnel responsible for photographic equipment are not trained in the proper maintenance and handling of these materials. Ignorance, neglect and neglect account for a significant percentage of the damage caused to photographs. Examples of negligence include repairing photos with pressure-sensitive adhesive tape, marking original prints with ink or felt pens, and presenting materials in inappropriate conditions. Negligence also includes the lack of a civil protection plan, inadequate security precautions, and poor collection management procedures that require valuable originals to be processed repeatedly. Negligence includes brutal manipulation during cataloguing, housing and visualization.

storage in a potentially explosive atmosphere; and property damage due to inadequate transport systems. Surprisingly, document scanners can be used to quickly scan large quantities of archival quality pages. Many may not expect a document scanner to be used to scan bound documents, but this approach can be a cost-effective and fast option compared to traditional book scanning. .