Preservation Metrics: Natural Aging

Image Permanence Institute Director, James Reilly, presents the brittle cracking of a book cover, the deterioration of a silver gelatin acetate negative, and the discoloration of two book pages as examples of Natural Aging. Natural Aging is one of the categories of decay considered by IPI's Preservation Metrics, algorithms that use the temperature and humidity conditions to rate the risk of potential damage to cultural heritage collection materials.