In 1979 a research project was undertaken at Rochester Institute of Technology to investigate the causes and mechanisms of deterioration in albumen photographic prints. Experiments showed that bad processing was not the cause of widespread deterioration. Results identify high relative humidity as the chief condition leading to instability of albumen prints. Also, alkaline conditions accelerated yellowing. More research must be done to identify safe enclosure materials and the effect of other environmental factors on stability. For storage, RH 30%-40% at 18°C is recommended, with paper enclosures of neutral, high alpha-cellulose paper without carbonate buffering. Uncoated polyester and cellulose triacetate also appear safe. See also 17-1648.