Many factors which influence the permanence of paper and papermaking materials can be tested and analyzed. Permanent paper must incorporate fibers of high quality, be near neutral or slightly alkaline, and be free of materials which promote deterioration. However, the complex composition of paper and the probability that numerous chemical reactions may take place preclude successful application of one or a few tests in estimating probable permanence. Recourse has been made to procedures based on accelerated aging or response to heating in which deteriorative conditions are integrated and reaction rates are increased. Possible uncertainties still remain because of the influence of moisture content during aging or heating and because the effect of temperature on reaction rates of the many components is essentially unknown. See also AATA 15-389.