Issues to be Considered for Photographic Materials
(Further questions should be directed to the Photograph Conservator, Conservation Division, Library of Congress - Andrew Robb 202 707-1175.)
Use of polyester or polypropylene sleeves inside paper enclosures:
DO NOT USE SLEEVES:
- When film base is acetate or nitrate.
All acetate film is unstable and degrades in normal (70° / 50%RH) environmental conditions. It should NOT be stored in plastic enclosures, unless temporarily, when handled by staff or researchers. Always place directly into paper enclosures. - When a flaking or friable film image needs housing. Place directly into a paper enclosure.
DO USE SLEEVES:
- For protection from abrasion and scratching during handling.
Before being handled by staff or researchers, B&W film and all color film need to be protected by plastic sleeves to reduce likelihood of abrasion and scratching. - For protection from scratching due to abrasion from the surface texture of the paper enclosure.
All film surfaces can be scratched. This is a concern for highly valuable, highly vulnerable, highly used film images. The plastic sleeves protect the film surface. - For prevention of moisture build-up on the surface of the film in cold storage during changing climate conditions. The use of plastic sleeves inside paper enclosures is necessary when transporting film images to and from cold storage vaults or in the case of humidity elevation in the vault.
Cool and cold storage:
ANSI recommendations for storage specify these conditions for
COOL STORAGE (35°-59°F at 30-40% rH):
Ideally all B&W film images (Master Images and Preservation Duplicates) go into cool storage.
COLD STORAGE (35°F or less at 30-50% rH):
Ideally all color images (Master Images, Preservation Duplicates and Service Copies) go into cold storage.
The lower the temperature, the slower the rate of deterioration. Therefore, cool storage will slow all forms of photographic deterioration, especially film base deterioration (acetate, nitrate), and silver or color dye deterioration. Cold storage slows deterioration more, especially for color dye images. Cool storage is useful for B&W acetate film in order to slow acetate deterioration. If B&W film is used frequently, the cool storage is preferable since the warm-up time to room temperature is less than for items stored at cold temperatures. Frequent cycling between cool/cold storage and room temperature is damaging to photographs. All color film, both positive and negative, needs to be stored in cold storage. Color dyes are unstable and will fade unless stored in cold storage. Cold storage will preserve color images indefinitely.
Cool and Cold Storage Vaults are very limited at LC.
Related issues:
Budget Concerns:
- Polyester and polypropylene sleeves are an added expense in housing a film collection. A difficult determination may have to be made as to whether or not a certain collection is of high enough value or rarity or if it is used extensively enough to deserve the extra cost of the plastic sleeves.
Policy of the Photoduplication Service:
- As part of its service, the Photoduplication Service provides 4"x5" color transparencies with polypropylene sleeves when delivered.
