put on
in error, or should it be necessary to retool part of the book after
it has been varnished, the varnish can be removed with spirits of
wine. Varnish acts as a preservative to the leather, but has the
disadvantage, if used in excess, of making it rather brittle on the
surface. It must, therefore, be used very sparingly at the joints. It
is to be hoped that a perfectly elastic varnish, that will not tarnish
the gold, will soon be discovered.

As soon as the varnish is dry the boards may be pressed, one at a
time, to give the leather a smooth surface (see fig. 83), leaving each
board in the press for some hours.

[Illustration: FIG. 89.]

After each board has been pressed separately the book should be shut,
and pressed again with pressing plates on each side of it, and with
tins covered with paper placed inside each board. Light pressure
should be given to books with tight backs, or the leather may become
detached.

If, on removing from the press, the boards will not keep shut, the
book should be pressed again with a folded sheet of blotting-paper in
each end. The blotting-paper should have the folded edge turned up,
and be placed so that this turned-up edge will be in the joint behind
the back edge of the board when the book is shut.

A small nipping-press suitable for giving comparatively light
pressure, is shown at fig. 89.

TOOLING ON VELLUM

Most covering vellum has a sticky surface, that marks if it is
handled. This should be washed off with clean water before tooling.
The pattern is blinded in through the paper as for leather, excepting
that the paper must not be pasted directly to the vellum, but may be
held with a band going right round the board or book. It is best to
glaire twice, and to lay on a small portion of gold at a time with
benzine. As vellum burns very readily, the tools must not be too hot,
and some skill is needed to prevent them from slipping on the hard
surface.

Vellum must not be polished or varnished.

INLAYING ON LEATHER

Inlaying or onlaying is adding a different leather from that of the
cover, as decoration. Thus on a red book, a panel or a border, or
other portion, may be covered with thin green leather, or only flowers
or leaves may be inlaid, while a jewel-like effect may be obtained by
dots, leaves, and flowers, tooled over inlays of various colours.
Leather for inlaying should be pared very thin. To do thi