Industrial paper testing methods are often directed toward the development of durable and permanent products. Conservation scientists in museums, libraries, and archives are more interested in evaluating materials, methods, and conditions which prolong the life of existing materials. Tests of the durability and physical integrity of paper can relate directly to the conditions of use. Because of the slow rate of cellulose degradation, these tests must be combined with accelerated aging in order to evaluate permanence. Accelerated aging should reproduce natural aging. The complex nature of the degradation process of paper makes the evaluation of accelerated aging conditions difficult. The effects of temperature an humidity must be known in order to determine what range of aging conditions accurately reproduce natural aging. Experiments which follow individual reactions provide a direct means of comparing aging conditions and a basis for predictions of the effects of specific storage conditions.