That is why we "saw-in" our books. The sawing-in is done with a broad saw; the so-called "tenon saw" being the one most generally used. The saw-cut must correspond exactly to the thickness of the cord to be used, should be less deep than wide, and should not take up too much glue when glueing up, as this might easily turn brittle. By inclining the saw to right and left alternately during sawing, the resulting cut will be something like this ¯¯¯¯¯/__\¯¯¯¯¯; this is the best and most usual form. The common practice of widening the cut by means of a coarse file gives a triangular cut like this ¯¯¯¯¯\/¯¯¯¯¯ which is objectionable, as the groove gets filled with glue, thus rendering the thread liable to break. As many cuts must be made in the book as there are cords to be used, besides the so-called kettle stitch at head and tail by which the thread is passed from one sheet to the other. Dividing the back for sawing-in is done by marking off 1 cm. from the head and twice as much from the tail and dividing the rest into equal portions with the dividers. An octavo should never be sewn on less than four cords, and a folio on six. If obliged to use less through low prices, then three must be taken as the minimum number, and that only in exceptional cases. If the books are very small—as, for instance, prayer-books and hymn-books less than 7 cm. in height—it may then be permissible to sew on two cords. The division for the different sizes for sawing-in is made as shown in Fig. 23.
| 6 cords = 9 divisions. | |
| 4 cords = 7 divisions. | |
| 3 cords = 6 divisions. | |
| 2 cords = 5 divisions. |
Fig. 23—Divisions for sawing-in.
The saw-cuts at the kettle stitch are less deep and quite narrow; they only mark the place where the thread is to pass in and out.
It may be wondered why the distances between the cords, when using four or six, are unequal; the reason for this will be explained when we come to the sewing of such sizes.
In sawing-in, the batch to be sawn is knocked up head and back and put between two boards—if the volumes are thin, several may be laid together—so that the back projects about 1/2 cm. beyond the edges of the boards. The first and last sheet of each volume have previously been laid aside, as these, with one exception, are not sawn-in.
Books and boards are now clamped in a small hand-press, which is screwed up by hand only. For convenience of working, the press with the screws is laid flat upon the table, so that the nuts are against the table edge. The press is propped up at the back by the press-jack. The divisions for the cords are marked on the back with a lead pencil after measuring with the dividers, and the cuts made according to the markings. If several volumes of the same size are to be sawn-in, the top sheet of the first batch sawn is used as a guide for marking the others, thus saving the work of measuring each one with the dividers. Where much sawing-in is done, a sawing-in machine is employed. The sheets are placed, backs downwards, in a moveable box, which is led over a system of circular saws.
After the work of sawing-in, the first and last sheets are replaced, the volumes again collated, and the end papers put in place; the sheets are now ready for sewing.
End papers are the blank leaves which the binder places at the beginning and end of a book. They vary according to the style of the book. Every end paper consists of a "fly leaf" (this lies over the title page in the book), the "paste-down," and in most cases of a "tear-off." For the stronger end papers and in half-leather bindings a cloth joint is used. Whilst dealing with these end papers, we must not forget the narrow guard; it is worked on the prepared end paper (as will be shown later) by folding over, and serves to enclose the title or end page with which it is sewn. The words joint, guard, and swell may here be more clearly explained, as they are used very frequently in the bindery. In the first place, we call the part where back and cover are joined by a sort of hinge "the joint," also strips of leather, cloth, &c., used for making this part are called "joints"; secondly, the slightly raised part of the back, caused by pressing or sewing, is shortly called "the swell"; and any strips of linen or paper fastened into the back of the book for hingeing maps, plates, &c., are called "guards."