Three weights of Irish linen thread, Nos. 15, 18 and 25, will answer for almost all books. If there are many sections and they are thin, a light-weight thread is used. If the sections are thick, or very few in number, heavier thread may be used. It should always be borne in mind that the back will contain, when finished, as many threads as there are sections, and the back, when finished, should not be materially thicker than the rest of the book. Silk of various weights and colors may also be used in fine work; it should always be slightly waxed before using.
The book should now be knocked up between two pieces of board about the same size, the square being used on the head, to see that it is about square; it is then screwed in the cutting press. Old covers will be useful here. The back must now, by means of the compass, be divided into proper squares. It is customary to divide an ordinary octavo into six panels, making five bands, the four central spaces being equal to each other, the one at the head a trifle longer, the one at the tail a bit longer than the one at the head. Each binder may have his own ideas as to proportion and, indeed, as to number of hands. The points where the cords are to come being determined as above, the square is used and a heavy pencil mark made across all the sections where each cord will fall. If sunken cords are to he used and false bands made, then a fine-toothed thin saw is to be employed, sawing on the lines just made, until the saw-cut will barely show on the inside of each section when opened. Care must be taken that the cut be not too deep (better have it too shallow) and that it is not deeper on one side of the back than on the other.
If raised cords are to be used, no sawing-in is done; but it is very useful to make a shallow cut instead with a sharp, thin knife, so that less difficulty is experienced in finding just where the needle is to pass through the sections when sewing. Over handing outside sections, to give strength where most needed. The first and last section should now be over handed with fine linen thread, with stitches one-quarter inch apart. After this is done these sections should he placed on the beating stone and tapped slightly to bury the threads somewhat in the paper. Kettle-stitch: For both styles of sewing, however, a mark must also be made about one-half inch from head and tail and also sawn (but very slightly). These are for the turn of the thread in sewing, making what is known as the kettle-stitch. The sewing frame is now prepared. If the book is sawn in, thin linen cords are used; if not sawn in, heavy English or Italian cord is needed. The number of cords in each case is the same. The proper number of cords are now fastened in the frame and tightened up (see diagram).
Place against the cords a thick pressing board, larger than the book to be sewn, so that the first section is raised up somewhat and handled more easily. The first section, being over-handed, is quite difficult to sew. It should be opened in the center and the needle passed through from center to back wherever a cord is to come (this preliminary work makes it more easy to pass the needle when sewing). Now lay this section, face down, on the frame, so the cords lie against the marks or cuts made on the section. The cords are to be adjusted to fit this spacing and then are tightened up. Sewing on sunken cords: As the operator sits before the frame the back of the section is toward him, head to the right. The left arm passing around or inside the left upright, as may be most convenient, the hand is placed in the center of section, holding it partly open; the right hand now passes the threaded needle into the kettle-stitch opening at head of section, is received by left hand and passed back through the first cut, the needle end coming out between the kettle-stitch and the first cord.
With the right it is now passed around the cord and back through the same cut. With the left hand it is again passed out through the next cut, around the cord and back, drawn up snugly from time to time so the cords are held tightly against the section, until it is finally passed out through the kettle-stitch opening at the tail. The next section is now laid on the first, held open with left hand, the needle passed through the kettle-stitch opening (next the tail), drawn up snugly and this section sewn as before.
Before passing to the remaining sections it is necessary to fasten the loose end of the thread which is still projecting from the first kettle-stitch opening. Steady the two sections with the left hand and pull each thread tight; then tie them together (they tie better if slightly moistened), cut off the original loose end and proceed with the sewing. The needle now being passed into thread drawn tight, it will be noted that this binds the ends of the three sections together. On emerging from the kettle-stitch at the tail of this section, the needle is passed between the second and first section (inside the thread lying in the cut for the kettle-stitch) and out toward the tail, the thread now forming a loop. Pass needle from below upward through loop and draw tight; this fastens the ends of these sections together. [sewing4.jpg] The ends of all sections must be tied to each other in this manner; but care must be taken not to draw the thread too tight, else the head and tail will be thinner than the central part of back, and will be so leaving a clean, straight strip of paste on the section. Let it set a moment or so, then bring the first section over, close it but do not use much pressure over the paste. Be sure the back edges of the two sections are quite evenly adjusted.
Treat the last section in a similar manner. Place the book between two pressing boards with a weight on it and leave for several hours, or overnight. The object of the two cardboard slips is to bring the weight on the pasted portion only and make a solid union. If this is not well done, it is liable to come apart when the book is opened. This also hides the thread used for Over-handing.