and of a durable kind, although for the
sake of cheapness it may be necessary to use skins with flaws on the
surface. Such flawed skins cost half, or less than half, the price of
perfect skins, and surface flaws do not injure the strength of the
leather. By sewing on tape, great flexibility of the back is obtained,
and much time, and consequent expense, in covering is saved. By using
a French joint much thicker leather than usual can be used, with
corresponding gain in strength.

To bind an octavo or smaller book according to the specification given
(III, page 307); first make all sections sound, and guard all plates
or maps. Make end papers with zigzags. After the sections have been
thoroughly pressed, the book will be ready for marking up and sewing.
In marking up for sewing on tapes, two marks will be necessary for
each tape. When there are several books of the same size to be sewn,
they may be placed one above the other in the sewing press, and sewn
on to the same tapes. It will be found that the volumes when sewn can
easily be slid along the tapes, which must be long enough to provide
sufficient for the slips of each. The split boards may be "made" of a
thin black mill-board with a thicker straw-board. To "make" a pair of
split boards the pieces of straw-and mill-board large enough to make
the two are got out, and the straw-board well glued, except in the
centre, which should previously be covered with a strip of thin
mill-board or tin about four inches wide. The strip is then removed,
and the thin black board laid on the glued straw-board and nipped in
the press. When dry, the made board is cut down the centre, which will
leave two boards glued together all over except for two inches on one
side of each. The boards then are squared to the book in a mill-board
machine. The back of the book is glued up, and in the ordinary way
rounded and backed. The edges may be cut with a guillotine. The ends
of the tapes are glued on the waste end paper, which should be cut off
about an inch and a half from the back. The split boards are then
opened and glued, and the waste end papers with slips attached are
placed in them (see fig. 72), and the book nipped in the press. To
form a "French joint" the boards should be kept about an eighth of an
inch from the back of the book. The book is then ready for covering.
The leather must not be pared too thin, as the French joint will give
plenty of play and allow the use of much thicker le