Today every progressive library binder has a special method of overcasting and each claims that his method is the best. Librarians, however, can see many points of resemblance between them, and few points of difference. In actual wearing qualities the sewing of one seems as good as that of another. When properly done the sewing prescribed by all of the methods is still in good condition when the books have to be withdrawn from circulation.
In overcasting, as in old-fashioned whipstitching, the sewer selects a certain number of sheets for sewing. Bands are placed on the sewing-bench as in regular sewing, though some binders claim that it is not necessary to sew either on bands or tapes. The sections are first perforated by a machine to facilitate the work of the sewer and to insure that all stitches shall be equidistant from the back of the book. So far as is known no machine for this purpose is on the market. It is certain, however, that the best binders have machines for this purpose. They have either designed their own machines or have adapted those made for other purposes. If the book is printed on thick, spongy paper it will increase flexibility if the paper is creased along the line of perforation.
Figure 5.—One kind of modern overcast stitch. There are others equally good. Note that each stitch extends through two sections.
It is difficult to give a description of modern overcasting which can be easily understood by one unfamiliar with sewing processes. The reader will be helped by looking closely at Figure 5 while reading the following description, but one can understand it best by seeing it done or by tearing a book apart and examining the sewing.
The first section of the book is sewed over and over in the same way as in the old-fashioned method of whipstitching, except that a great many more stitches are taken. The second section, when placed on the first, is also sewed over and over but a certain number of stitches are also made which connect the second section with the first. In the same way the third section is sewed to the second and so on through the book, so that when the book is finally sewed it is tight and compact; its weakness lies in the paper itself, not in the sewing. Some binders add three kettlestitches at the end of the book instead of one, believing that when all kettlestitches are placed in one sawcut the swell at the head and tail of the book is too great.
Figure 6.—From "About Public Library Books and Their Binding" by Cedric Chivers.
Figure 7.—Sewing on tapes. Sawcuts made only for kettle stitches. Based on illustration in Report of the Committee on Leather for Bookbinding. Edited for Society of Arts, London, 1905.