but velvet never takes the sharpness of the design on account of the pile, so that as a rule it is left in its natural state.
Vellum.—The Dutch, as a nation, appear to have been the first to bind books in vellum. It was then a simple kind of casing, with hollow backs. A later improvement of theirs was that of sewing the book on double raised cords, and making the book with a tight back, similar to the way in which our flexible books are now done, showing the raised bands. The ornamentation was entirely in blind, both on the back and sides, and the tools used were of a very solid character.
This art of binding in vellum seems to be entirely lost at the present day; its imperishable nature is indeed its only recommendation. It has little beauty; is exceedingly harsh; and little variety can be produced even in the finishing.
There are two or three kinds of vellum prepared from calf skins at the present day, thanks to the progress of invention. First, we have the prepared or artist's vellum, with a very white artificial surface; then the Oxford vellum, the surface of which is left in its natural state; the Roman vellum, which has a darker appearance. Parchment is an inferior animal membrane prepared from sheepskins after the manner of vellum, and this is very successfully imitated by vegetable parchment, made by immersing unsized paper for a few seconds in a bath of diluted oil of vitriol. This preparation resembles the animal parchment so closely that it is not easy to distinguish the difference. It is used very extensively in France for wrappering the better class of literature, instead of issuing them in cloth as is the custom here.
The method of finishing vellum is altogether different to leather. On account of its very hard and compact nature, it requires no other ground or preparation than glaire for gold work.