Fig. 7

In (a), tensile curves (solid lines) obtained at 20 and 80% RH for the animal glue-treated degraded cotton canvas tested in the warp direction. Linear fitting (dashed lines) of the curves was carried in the region of interest and used to calculate Young’s moduli shown in (b). Young’s moduli are given for degraded cotton canvas before and after treatment with CNF, animal glue and Beva^® 371 measured at 20 and 80% RH. The difference ΔE_{20–80% RH} calculated between Young’s moduli measured at 20% RH (i.e., E_{20% RH}) and 80% RH (i.e., E_{80% RH}) for untreated and treated degraded cotton canvases are tabulated in (c)