Impressing of skins in vacuo - to modify relief, appearance or the grain

摘要

Impressing process is applied to skins for modifying the relief, the appearance of the grain. EAch skin is treated to the usual preparatory processes of tanning, buffing to equalise the thickness, dressing and, possibly, dyeing; it is then placed, with the flesh side down, on the heating plate of a vacuum drying appts. The impress to be reproduced is placed between the hair side of the skin and the cushion of the airlight cover; the latter is closed and the skin subjected to a drying operation in vacuo according to the usual parameters except that the duration is extended. During the course of the operation, the impress is deeply reproduced on the skin; this has a lasting effet because the constitutive fibres of the skin are ruptured locally by the heat and the suction. The remarkable strength of the grain thus obtd. enables such impressions to be made on thin, pliable skins without the need for costly fixation processes or chemical treatments. The skins after-treatment can be subjected to a wet process and dyed to obtain a two-tone effect that could not be obtd. hitherto. The depressions can be given a lighter shade than the genral tint.