Page:The Art of Bookbinding, Zaehnsdorf, 1890.djvu/110

80 ; but gold-beaters' skin is now used instead of vellum; and so by continual beating and cutting up, the proper thickness is arrived at. If the gold is held up to the light, it will be found to be beaten so thin that it is nearly transparent, although when laid on any object it is of sufficient thickness to hide the surface underneath. It has been estimated that the thickness of the gold leaf is only 1/280000 of an inch.

To gild the edges, the book should be put into the press straight and on a level with the cheeks of the press between cutting boards, the boards of the book being thrown back. The press should be screwed up very tightly, and any projection of the cutting boards should be taken away with a chisel. If the paper is unsized or at all spongy, the edge should be sized and left to dry. This may be ascertained by wetting a leaf with the tongue: if spongy, the moisture will sink through as in blotting paper. The edge should be scraped quite flat and perfectly even, care being taken to scrape every part equally, or one part of the edge will be hollow or perhaps one side scraped down, and this will make one square larger than the other. When scraped quite smoothly and evenly, a mixture of black lead and thin glaire water is painted over the edge, and with a hard brush it is well brushed until dry.

The gold should now be cut on the gold cushion. Lift a leaf out of the book with the gold knife, lay it on the gold cushion, and breathe gently on the centre of the leaf to lay it flat; it can then be cut with perfect ease to any size. The edge is now to be glaired evenly, and the gold taken up with a piece of paper previously greased by drawing it over the head. The gold is then gently laid on the edge, which has been previously glaired. The whole edge or end being done, it is allowed to get perfectly dry, which will occupy some two hours.

Before using the burnisher on the gold itself, some gilders