What effect can the environment have on a photographic collection?
Various aspects of the environment, such as relative humidity, temperature, air purity, and light, influence the stability of a photograph collection. Relative humidity is the single most important factor in preserving photographs from chemical deterioration. High relative humidity speeds up detrimental chemical reactions, leading to much of the fading and discoloration visible in photograph collections. Relative humidity should be kept below 50%; ideally it should be 35%. Stable conditions are very important.
