Many makers send out boards bevelled right from one side to the other. This kind is very unsuitable and has many disadvantages. The boards must not be made from wood of very open grain, and firs and oaks must not be used. The boards are to be somewhat longer than the edge about to be treated, so that the edge may be as firm and tight as possible and at the same time easy to work upon; two outer boards are added to those regularly used, as shown in Figs. 49 and 50.
The inner boards are quite flush with the book: the latter must on no account stand back. The outer boards are about 3 mm. behind the others; the book is so placed in the press, and here again the book and boards must be exactly level with the press cheeks. The press is then screwed up as tight as possible. If the inner boards have not perfectly straight edges they must be planed down.
Figs. 49 and 50--Arrangement of flat and rounded edges.
The edges are to be scraped down quite smooth with a scraper or, if necessary, with a knife; the scraper must not be sharpened for this purpose as the carpenter sharpens his tools, that is, not to a cutting edge but as though it were for carving, until a bevel (or turned edge) of about 3 mm. has been ground. The edge thus gets a turned edge, with which the book is scraped. If it should cease to "take," the old edge is rubbed down with a steel and a new one made by a few firm strong rubbings. The edge should be wetted a little to prevent its heating. Flat edges are scraped with a flat scraper, rounded edges with one suitably rounded. In this case the round of the blade must be more decided than that of the edges, as it would otherwise be impossible to get into all parts of the edges. Scraping with pieces of glass is an antiquated, clumsy method.
When scraping, the press should lie flat on the table edge, the other end being supported by the press-jack. In scraping, the blade is held in both hands, scraping away from the worker, the scraper sloping forwards. The press must be made immovable. Scraping is continued until all places have been gone over and the whole is perfectly smooth and even. When this is accomplished, the edges are thinly coated with paste, which is well rubbed in along the sheets with a bundle of waste paper until the edges look as if burnished. It is advisable to damp the edges before scraping, as the blade then takes hold more uniformly.