Reports about the permanence of <i>washi</i> (Japanese paper) are reviewed and the effect of <i>dosa</i> on the deterioration of <i>washi* 1 studied by accelerated aging treatments. * 2Dosa</i>, which consists of animal glue and alum, is utilized as the glue size for <i>washi</i>. When the pH of <i>washi</i> goes below five, deterioration, as determined by folding endurance and tensile energy absorption (TEA), increases radically with the decrease of the pH. The rate of discoloration of <i>washi</i> showed the same tendency. An important factor in the permanence of <i>washi</i> is its buffering ability which diminishes the effect of acid on the pH. The amount of carbohydrates in <i>washi</i> showed little change after accelerated aging treatment. -- AATA