book, as an excess is
apt to stain the leather and to make the gold dull. After experiment
it has been found that cocoanut oil stains the leather less than any
other grease in common use by bookbinders, and is more readily washed
out by benzine.

[Illustration: FIG. 87.]

If the gold cracks, or is not solid when pressed on the book, a second
thickness should be used. This will stay down if the under piece is
lightly breathed upon.

For narrow strips of gold for lines, a little pad covered with soft
leather may be made, as in fig. 87.

It will be found of advantage to first use the bottom leaf of gold in
the book and then to begin at the top and work through, or else the
bottom leaf will almost certainly be found to be damaged by the time
it is reached. The gold used should be as nearly pure as it can be
got. The gold-beaters say that they are unable to beat pure gold as
thin as is usual for gold leaf; but the quite pure gold is a better
colour than when alloyed, and the additional thickness, although
costly, results in a more solid impression of the tools.

The cost of a book of twenty-four leaves three and a half inches
square of English gold leaf of good ordinary quality is from 1s. 3d.
to 1s. 6d., whereas the cost of a book of double thick pure gold leaf
is 3s. to 3s. 6d. For tooled work it is worth paying the increased
price for the sake of the advantages in colour and solidity; but for
lines and edges, which use up an immense amount of gold, the thinner
and cheaper gold may quite well be used.

Besides pure gold leaf, gold alloyed with various metals to change its
colour can be had. None of the alloys keep their colour as well as
pure gold, and some of them, such as those alloyed with copper for red
gold, and with silver for pale gold, tarnish very quickly. These last
are not to be recommended.

For silver tooling aluminium leaf may be used, as silver leaf
tarnishes very quickly.

When the gold is pressed into the impressions of the tools with the
pad of cotton-wool, they should be plainly visible through it.

The pattern must now be worked through the gold with the hot tools.
The tools are taken from the stove, and if too hot cooled on a pad as
for blinding-in. The heat required to leave the gold tooling solid and
bright and the impressions clear will vary for different leathers, and
even for different skins of the same leather. For trial a tool may be
laid on the pad until it ceases to hiss, and o