The biggest enemies of the photographs are light, humidity and heat. Often a combination of factors leads to deterioration in photograph’s quality.
High Temperature and Relative Humidity
Among the most destructive factors that affect photographs are high temperature and relative humidity . Photographs
should not be kept in temperatures above 70 degrees Fahrenheit and relative humidity above 60% for long periods.
Daily, drastic temperature changes (such as those that may occur in an attic) and continuously damp areas (such as
basements) should also be avoided.
Photograph's emulsion is composed of gelatin. High humidity and heat favour
growth of mold and fungi. These elements also cause base materials to deteriorate quickly. Cold temperatures
(refrigeration) are preferable, especially for color photos, but only if humidity can also be controlled. Standard
refrigerators have a high relative humidity and are not a good place to store photographs.
Direct sunlight and strong light are very destructive to photographs. It is best to avoid exposure to direct
sunlight and to use ultraviolet filters on fluorescent lights. If you wish to display photographs in a sunny area of
your house, you might consider framing a copy of the photo and storing the original in a safe place.
There are a few things you can do to protect your photographs from flood, fire, and other natural disasters. Storing
them up off the floor is relatively simple and can help tremendously in case of minor flooding. Storage in an enameled
steel file cabinet can prevent photographs from being crushed and offers some safety from water and fire damage. You
may want to consider a safe deposit box for extremely valuable photographs in case of a disaster.