MAINTAINING A SUITABLE ENVIRONMENT
Photographic materials require a cool, dry, well-ventilated storage environment. High temperature and relative humidity increase deterioration and promote the growth of mould and mildew, which could mar surfaces and break down binder layers. Avoid storing photographs in the attic, the basement, or along the outside walls of a building, where environmental conditions are more prone to extremes and fluctuations and where condensation may occur. In some storage situations, seasonal adjustments such as dehumidifiers in the summer or fans to promote air circulation may be necessary to improve problematic environmental conditions.
CHOOSING STORAGE ENCLOSURES
Keep photographic materials in enclosures that protect them from dust and light and provide physical support during use. Chemically stable plastic or paper enclosures, free of sulphur, acids, and peroxides, are recommended. Plastic sleeves should be constructed of uncoated polyester, polypropylene, or polyethylene. For most photographic materials, un-buffered paper enclosures are preferred over buffered enclosures.
Alkaline buffering is added to archival storage papers to absorb acidity from the stored material or the environment surrounding it. However, the buffering in alkaline papers, so un-buffered paper is recommended for most processes, may alter some photographs. Film-based negatives, which can produce acidic gasses as they age, should be placed in archival, buffered enclosures and stored separately from other photographic materials. Store cased objects, such as daguerreotypes and ambrotypes, in their original cases or frames with the addition of custom-made, four-flap paper enclosures to reduce wear and tear on fragile cases. Place individually housed prints, negatives, and cased objects in acid-free, durable boxes that will afford further protection from light, dust, and potential environmental fluctuations.
Photographs should be protected from extended exposure to intense light sources. Limit exhibition times, control light exposure, and monitor the condition of the photographs carefully. Prolonged or permanent display of...