Fig. 12

Curling of contemporary parchment specimens—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. Samples were exposed to RH levels lower than 50% for 18 h and then stabilized at 50% for at least 48 h (squares). Samples were exposed to RH levels higher than 50% for 2 h and then stabilized at 50% RH for 6 h (triangles)