State Historic Site
By Site Superintendent Cynde Georgen; from Trail End Notes, July 2003
SUMMER IS A time of family gatherings and class reunions. One of our favorite things to do at such events is to get out old photographs and take a walk down Memory Lane. Too many of us, however, eagerly pull that box of snapshots down from the attic only to look in dismay at the discolored, faded and brittle scraps of paper inside – the result of heat, light and humidity damage.
Here are a few guidelines for taking care of your precious photographic memories, courtesy of the Light Impressions Company and the Wyoming State Archives.
Temperature & Humidity Photographs should not be stored in areas where the temperature rises above eighty degrees or where the humidity is greater than sixty percent. So where do most of us store our photographs? In the (hot) attic or the (damp) basement! Ideally, storage temperature should be about 65-70 degrees, with a relative humidity somewhere between 30-40 percent.
Lights, Camera, Disintegration! Most photos are printed on light-sensitive, chemically-treated paper. When you expose such paper to more light, the chemicals start to react. While some fade, others go dark. You need to avoid prolonged exposure to light whenever possible, but you need to be particularly careful about sunlight and fluorescent light. Use ultraviolet filters over fluorescent lights when photos are being displayed for more than a few minutes.
Harmful Materials & Fumes The sensitive chemicals which create the photographic image can be damaged not only by light, heat and humidity, but by common household materials as well. The list includes paper envelopes, rubber bands, newspapers, wood, paper clips, cardboard and some plastics. Vapors from paints, plywood, cleaning supplies and insecticides are also very damaging. Store your photos in acid-free or Mylar envelopes inside a baked enamel steel box or cabinet. If you have photographs in those sticky-page albums that were popular in the 1970s, remove them as soon as possible – if you still can; the glue tends to turn permanent after awhile. As for plastic photo album pages, if you can smell the plastic, don’t use them! Bad plastic is far, far worse than no plastic.
Critters & Other Growing Things Insects such as cockroaches and silverfish like to nibble on both the photographic paper and the emulsion gelatin on top. If the photos get damp, fungi and molds can grow. These not only damage the images, but also serve as food for the critters! Mice and weevils have also been known to appreciate a good emulsion, so watch out!
Sticky Fingers & Dust Prints Photos, negatives and slides must also be protected from dust, dirt, fingerprints, scratches and environmental/chemical deterioration. Since many contaminants, including sulfur and acidic oils, can be transferred from your fingers, you should wear white cotton gloves and only handle the photos and negatives by the edges.