Chemical, physical, and mechanical properties of paper affect decisions regarding its care and treatment. Changes over time in properties including stiffness, strength, and elasticity are examined using both naturally and artificially aged samples. These properties are determined as a function of environmental conditions for new and aged samples. The rate and nature of chemical degradation processes as a function of environment are correlated with changes in physical properties. The results of appropriate accelerated aging conditions correlate with those of natural aging. The results can be used to determine physically safe ranges for the storage of paper artifacts, and to indicate how conditions within this range affect the rate of changes over time.