rence or daily use is required, I should sew a book flexibly. Some binders sew their books in the ordinary way, and paste the leather directly to the back, and thus pass it for flexible work; but I do not think any respectable house would do so. A book that has been sewed flexibly will not have any saw cut in the back, so that on examination, by opening it wide, it will at once be seen if it is a real flexible binding or not.
Intelligence must, however, be used; a book that has already been cased (or bound and sewn on cords) must of necessity have the saw cuts or holes, and such a book would show the cuts.
There is another mode called "flexible not to show." The book is marked up in the usual way as for flexible, and is also slightly scratched on the band marks with the saw; but not deep enough to go through the sections. A thin cord is then taken doubled for each band, and the book is sewn the ordinary flexible way; the cord is knocked into the back in forwarding, and the leather may be stuck on a hollow back with bands, or it may be fastened to the back itself without bands.
However simple it may appear in description to sew a book, it requires great judgment to keep down the swelling of the book to the proper amount necessary to form a good backing groove and no more. In order to do this, the sheets must from time to time be gently tapped down with a piece of wood or a heavy folding-stick, and great care must be observed to avoid drawing the fastening of the kettle stitch too tight, or the head and tail of the book will be thinner than the middle; this fault once committed has no remedy.
If the sections are very thin, or in half sheets, they may, if the book is very thick, be sewn "two sheets on." The needle is passed from the kettle stitch to the first band of
- See chapter on Lining up.