Fig. 13

Curling of historical parchment specimens from a nineteenth century Abyssinian manuscript H7—expressed as a standard deviation of local surface curvatures—after they were exposed to a given RH level and then stabilized back at 50% RH. Exposure times are the same as in the case illustrated in Fig. 12. The degree of curling of the historical specimens, prior to the experiments, are represented by points at 50% RH