Photographs - 75

Photographs can be the most poignant of cultural objects, and yet few people stop to think about how diverse they may be. Photographs can be negative or positive images; the majority are found on supports made from paper, glass or film, but occasionally they may be on a metal, leather or textile base. Frequently, they are also associated with frames, albums, cases and even jewellery. In most photographs the main image-forming substance is silver, but dyes and pigments are found in colour photographs and in digital prints.

Photographs frequently consist of multiple layers, each layer containing different substances which behave in a variety of ways. This complex structure can make certain types of deterioration untreatable: what might be beneficial to one layer may be harmful to another. Consequently, the first line of defence for the owner is to prevent problems occurring in the first place.

Photographic conservators have wide knowledge of photographic techniques; they can identify processes and materials used in your object or collection as a preliminary to improving storage or carrying out treatment.