One of the most important factors affecting the preservation of photographs are the considerations of storage and display conditions. This includes what they are stored or enclosed in, the area in which they are stored, and the manner in which they are displayed.
Although the sun and it’s Ultra-Violet rays are most harmful to color photographs, heat and humidity will accelerate the deterioration of the dyes also. The best and proper way to store color photographs is in a dry, dark chamber and the temperature should be below zero degrees Fahrenheit. Most of us don’t have such a “chamber” but the cooler and darker the better.
Processed negatives, slides and prints should be enclosed in special envelopes, sleeve file folders, or albums to protect them from dirt and physical damage and to assist with identification and handling. Avoid photo albums with storage sleeves made with polyvinyl chloride as chemical out-gassing can damage the prints. Only the following plastics have been considered safe to use in association with photographs: Polyester, Mylar, Polypropylene, Polyethylene, Tyvek and Cellulose Triacetate. Look for albums designated as “archival quality”. When using scrapbooks make sure you use archival quality acid-free pages, protectors, adhesives and embellishments.
If you want to display a photo, it is best to make a copy and display the copy, while preserving the original. When displaying a color photo – make sure it does not face a window, or be sure to use UV protective glass.
If it is precious one-of-a-kind photo, consider having a black & white copy made and have it printed on a fiber paper vs. resin coated paper. Then have this print hand colored. The fiber paper and hand-coloring can last 100 to 300 years if stored properly because coloring uses pigments, not dyes, and pigments have greater archival properties than dyes.
For photos that matter, avoid a 60 minute type developer and find a developer that can archivally processes the film; generally a custom photo lab. Archival quality means that it will last at least 100 years or more (if properly stored). Ask the custom lab how long they wash the negatives. If it is not at least ONE HOUR washing time, then the chances are that it will not be archival processing.