The Role of Gelatin in Paper Permanence

Abstract

In William Barrow's classic study (1974) of historical paper specimens, he examined a number of factors that affect the stability of naturally aged papers, including cellulose fiber purity, alum content, amount of alkaline carbonate reserve, and pH. Barrow did not, however, investigate the effect of gelatin levels in his papers, and others have undertaken only limited research on the topic. In the study reported here, 40 historical paper specimens were analyzed to determine their gelatin content. Data from measurements of L* light-to-dark values, surface pH, and calcium content were compared with gelatin content. The data provided by these analyses show that both the appearance and the permanence of the papers may be affected by their gelatin content; avenues of further investigation in this area are outlined.