pts, in
many of which the sections are very thick. An advantage of this
method is, that the twist round the double cord virtually makes a knot
at every band, and should a thread at any place break, there is no
danger of the rest of the thread coming loose. This is the only mode
of sewing by which a thread runs absolutely from end to end of the
sections. The headband sewn at the same time, and so tied down in
every section, is firmer and stronger than if worked on in the way now
usual. In the fifteenth century it was the custom to lace the ends of
the headbands into the boards in the same way as the other bands. This
method, while giving additional strength at the head and tail, and
avoiding the somewhat unfinished look of the cut-off ends of the
modern headband, is, on the whole, of doubtful advantage, as it is
necessary to cut the "turn in" at the point where strength in the
leather is much wanted.

At fig. 32 is shown in section the three methods of sewing mentioned.
A is the old sewing round double bands; with the headbands worked at
the same time with the same thread; B is the modern flexible sewing,
and C the common sawn-in method.

[Illustration: FIG. 32.]

Books that are very thin or are to be bound in vellum, are best sewn
on tapes or vellum slips. The easiest way to set up the sewing-frame
for such sewing is to sling a piece of wood through two of the lay
cords, and to pin one end of the vellum or tape band round this, pull
the other end tight, and secure it with a drawing-pin underneath the
frame. The sewing, in the case of such flat bands, would not go round,
but only across them. To avoid undue looseness, every three or four
threads may be caught up at the back of the band, as shown in fig. 33.

[Illustration: FIG. 33.]

MATERIALS FOR SEWING

The cord used should be of the best hemp, specially made with only two
strands of very long fibres to facilitate fraying out. For very large
books where a double cord is to be used, the best water line will be
found to answer, care being taken to select that which can be frayed
out. If tape is used it should be unbleached, such as the sailmakers
use. Thread should also be unbleached, as the unnecessary bleaching of
most bookbinder's sewing-thread seems to cause it to rot in a
comparatively short time. Silk of the best quality is better than any
thread. The ligature silk, undyed, as used by surgeons, is perhaps the
strongest mat