Another simple way of keeping a vellum book shut is shown at [fig. 77]. A bead is attached to a piece of gut laced into the vellum, and a loop of catgut is laced in the other side, and looped over the bead as shown.
If the book is to have stiff boards, and the vellum is to be pasted to them, it is best to sew the sections on tapes or vellum slips, to back the book as for leather, and to insert the ends of the slips in a split board, leaving a French joint, as described for library bindings. Vellum is very stiff, and, if it is pasted directly to the back, the book would be hard to open. It is best in this case to use what is known as a hollow back.
Fig. 77.
To make a hollow back, a piece of stout paper is taken which measures once the length of the back and three times the width. This is folded in three. The centre portion is glued to the back and well rubbed down, and the overlapping edges turned back and glued one to the other ([fig. 78]). This will leave a flat, hollow casing, formed by the single paper glued to the back of the book and the double paper to which the vellum may be attached. Or it is better to line up the back with leather, and to place a piece of thick paper the size of the back on to the pasted vellum where the back will be when the book is covered.
Fig. 78.
When the book is ready for covering, the vellum should be cut out and lined with paper. In lining vellum the paste must be free from lumps, and great care must be taken not to leave brush marks. To avoid this, when the lining paper has been pasted it can be laid, paste downwards, on a piece of waste paper and quickly pulled up again; this should remove surplus paste and get rid of any marks left by the brush. When the vellum has been lined with paper, it should be given a light nip in the press between blotting-paper, and while still damp it is pasted, the book covered, and the corners mitred. A piece of thin string is tied round the head-caps and pressed into the French joint.