The book is placed back of the sewing bench with the fore-edge toward the sewer and with the first section on top. The first section (i. e. the end paper) to be sewed is then turned over, opened in the middle by the left hand, and placed on the sewing bench. The sewer, as she faces toward the right, with the right hand passes the needle from the outside through the sawcut for the kettlestitch, where it is taken by the left hand along the inside of the section and passed out on the near side of the first band, then in again on the far side of the first band, along the inside of the section to the second band, where the process is repeated; and so on, bringing the needle out in the far kettlestitch. (Fig. 2.) The thread is pulled tight at each stitch and about two inches of thread is allowed to hang from the first kettlestitch. In some few cases it may be advisable to bring the needle out on the far side of the band and in again on the near side, thus entirely encircling the band with the thread. The next section (i. e. the fly-leaves) is then laid on and the process repeated, except that the sewing proceeds from the far end to the near end. When the thread is brought out of the kettle stitch of the second section the end of the thread left projecting from the first section is securely tied to it, and the sewer proceeds with the third section. This will be the first signature of the book. On reaching the last sawcut at the far end in the third section the needle is put between the second and first sections carrying the thread down in such a way as to form a buttonhole stitch. (Fig. 3.)
Figure 3.—Kettle stitch.
All other signatures are sewed in the same way, the last section sewed being securely fastened to the others. It is possible to sew a number of books one after another without removing them from the sewing-bench. If the back swells unduly the sections can be pounded down with a piece of wood, care being taken not to drive them inward. The sewing should be neither too loose nor too tight. If too loose a firm, compact book cannot be made; if too tight the threads may break in the process of backing. Bands are allowed to project about an inch on each side of the book.
Formerly it was the practice of some binders to sew in a way technically called "two-on." This simply means that the sewer when reaching the middle of the signature, passes the needle into the corresponding sawcut of the signature above and sews through to the other end. This always leaves an end of a signature unsewed. This way of sewing is permissible on books which have a large number of thin signatures, in order to prevent the thread from unduly swelling the back. It is never permissible on other books.
The foregoing account gives a very brief description of ordinary sewing. It is easily understood when once seen. Librarians who have charge of binding should keep the process thoroughly in mind for it is the most important single process in the making of a book. Such sewing will be used on a large number of books which have to be rebound, but a still larger number, practically all fiction and juvenile books, should be sewed in a different manner; that is, with some kind of an overcast stitch.
Overcasting. The modern overcasting stitch resembles in principle the old-fashioned whipstitching, but differs radically in actual performance. It is exceedingly strong, while the old-fashioned whipstitching is not. It has been objected that modern overcasting takes away much of the flexibility of a book and that books once sewed in this way can never be rebound. It is true that an oversewed book is not as flexible as one sewed through the signatures, yet most of them are more flexible than one might suppose. It is also true that the book can never be rebound, but if the overcasting is properly done, the sewing will last until the book is discarded. It is for this reason that it is used on practically all fiction and juvenile books.
According to the old-fashioned method of whipstitching it was the custom to cut off the backs of signatures, glue them slightly, take a few leaves and sew them over and over making five or six stitches to a section, as shown in Figure 4. The next section was then sewed in the same way, but it was not joined in any way to the section beneath except by the kettlestitch and occasionally by a little paste. When sewed in this way the leaves inside of each arbitrary section would open only as far back as the threads of the stitches, while between the sections the book would open to the back of the section. If paste had been used the strain of opening tended to pull the leaves apart. If the book was subjected to hard wear the thread cut into the paper.
Figure 4.—Old-fashioned whipstitching. Each section is sewed separately.