3rd. Burnishers.—These are made of agate stone, and can be purchased of any size. A flat one, and two or three round ones, will be found sufficient. They should have a very high polish.
4th. Glaire Water or Size.—The white of an egg and a tea-cup full of water are well beaten together, until the albumen is perfectly dissolved. It must then be allowed to stand for some hours to settle, after which it should be strained through a piece of linen which has been washed; old linen is therefore preferred to new.
5th. Scrapers.—Pieces of steel with the edge or burr made to turn up by rubbing the edge flat over a bodkin or other steel instrument, so that when applied to the edge a thin shaving of paper is taken off. The beauty of gilding depends greatly on proper and even scraping.
6th. The Gold Leaf.—This is bought in books, the price according to quality; most of the cheap gold comes from Germany. I recommend the use of the best gold that can be had; it being in the end the cheapest, as cheap gold turns black by the action of the atmosphere in course of time.
The method of preparing the gold[7] is by making an alloy: gold with silver or copper. It is drawn out into a wire of about six inches in length, and by being passed again between steel rollers is made into a ribbon. This ribbon is then cut into squares and placed between vellum leaves, about four or five inches square, and beaten with a hammer somewhat like our beating hammer, until the gold has expanded to the size of the vellum. The gold is again cut up into squares of about one inch, and again |80| interleaved; 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.
[7] Although this has practically nothing to do with the art of bookbinding, it is always advisable for a workman to know something about the tools and materials he uses.
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.
Book-edge Burnishers.