Quick burnishing must always be avoided; it heats the gold, which rubs off under the burnisher, and causes holes which can never be remedied.

As soon as one length has been burnished, the waxed cloth must be applied before proceeding further.
Slight flaws in the gold itself, or due to bubbles in the glair, may be put right by touching the faulty places with a small brush dipped in rectified spirit and immediately laying on a piece of gold; if the edges had not yet been gone over with the waxed rag, it would be sufficient to breathe on the place, lay on the gold, and burnish under paper. This need only stand a few minutes, as it quickly evaporates, and may then be burnished again at once, first with, then without, the tracing paper. It must be observed that such faulty places must be burnished in the direction of the - sheets, never crosswise.

Rounded edges are more difficult to work; the scraping alone being more troublesome. Each piece of gold is halved, laying on each time a little beyond the deepest part of the round. The press is so lowered as to give a decided slope to the half of the edge to be operated upon. The gold is cut to a little more than half width, and only the under side to a little beyond the middle is glared, which in this case must be done very freely. The strips of gold-leaf are laid on as before. .When one side has been covered with gold, the press is turned and the other half of the round similarly treated. Care must be taken that there is always a liberal supply of glair in the depth of the round. To drain off the superfluous glair the press is placed so that the glair runs off on the long side; the gold is in consequence better taken up in the round.

Burnishing is here also done under a piece of paper, and it is better to work crosswise, first one half to the centre of the round and then the other. Only thin books are burnished along the edges with a round burnisher. After the round edges have been burnished crosswise they are burnished with the round burnisher.

Burnishers are made of agate or of bloodstone; the latter is said to produce a higher polish, but this may be due to our being more accustomed to its use. In selecting burnishers the flat ones should not be too wide and the strongest of the curved ones should be taken.

Top and bottom edges undergo the same treatment in gilding as the flat fore-edge, except for a few slight necessary differences in the method of fixing the book. In the first instance, long boards are used instead of the outer boards these protect the book from injury. The boards (the short sides of cross-boards are often used instead) are laid exactly in the groove at the back, but the outer boards are set back so that they are exactly in a line with the depth of the round edge. If this precaution is neglected, the chances are that little ridges will appear in the fore-edge where pressure has been applied. Fig. 51 shows the arrangement in the press.

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