Figs. 49 and 50—Arrangement of flat and rounded edges.
The edges are to be scraped down quite smooth with a scraper or, if necessary, with a knife; the scraper must not be sharpened for this purpose as the carpenter sharpens his tools, that is, not to a cutting edge but as though it were for carving, until a bevel (or turned edge) of about 3 mm. has been ground. The edge thus gets a turned edge, with which the book is scraped. If it should cease to "take," the old edge is rubbed down with a steel and a new one made by a few firm strong rubbings. The edge should be wetted a little to prevent its heating. Flat edges are scraped with a flat scraper, rounded edges with one suitably rounded. In this case the round of the blade must be more decided than that of the edges, as it would otherwise be impossible to get into all parts of the edges. Scraping with pieces of glass is an antiquated, clumsy method.
When scraping, the press should lie flat on the table edge, the other end being supported by the press-jack. In scraping, the blade is held in both hands, scraping away from the worker, the scraper sloping forwards. The press must be made immovable. Scraping is continued until all places have been gone over and the whole is perfectly smooth and even. When this is accomplished, the edges are thinly coated with paste, which is well rubbed in along the sheets with a bundle of waste paper until the edges look as if burnished. It is advisable to damp the edges before scraping, as the blade then takes hold more uniformly.
Then bolus is mixed with glair as a body colour, laid on sparingly, very evenly, and free from streakiness, using a thick hair brush for the purpose. Bolus is sold to the trade ready prepared under the name "Poliment." Some time before using, it should be scraped into a suitable vessel and mixed with glair. The latter is prepared by adding the white of an egg to 1/4 litre of water and beating to a froth. It is then strained through a piece of linen or, better, through a filtering paper.
After the bolus ground has dried (which takes a few minutes) the gold is laid on. There are various methods of doing this. The surest and quickest way is to lay it on with the gilder's tip.
A row of long badger hairs is glued between two pieces of cardboard; this is drawn a few times over the hair of the head, which makes it take the gold easily. Gilders' tips are to be had at any colour dealer's. Gold is taken from the gold book, laid upon the gold cushion, and cut into suitable strips with the gold knife. The gold cushion consists of a piece of calf stretched raw side out on a board. Between the leather and the board there is placed a pad of cotton wool, and over the wool a pad of blotting-paper. The gold knife is a thin, pliant, two-edged knife without a sharp edge, in fact it is better to blunt the fore-edge from time to time by rubbing it on a polished steel. If the knife is too sharp it will cut the leather cushion. Taking the gold from the book will not be found a very easy task. The top leaf covering the gold is turned back, the book with the uncovered leaf of gold laid on the cushion, and the book slowly lifted up. The gold-leaf remains flat upon the cushion and may be cut with the knife as required. If a draught has turned the gold-leaf over or made it lie unevenly, it may be righted by lightly tapping with the knife on the cushion near the gold; careful breathing on the centre of the leaf will help in more awkward cases—the rest must be learned by practice. Never attempt to take hold of gold-leaf with the fingers; only the experienced workman knows how to carry gold-leaf with a finger.
For gilding the edges the deep red gold is always used, or else the so-called orange gold, which is somewhat lighter in tone, but never the lemon or green gold.
For flat gilt edges the gold is cut about 3 mm. wider than the book and into as many strips as would make up the length of the edge if joined together.
Before laying on the gold, the bolused edge is brushed down with a hard clothes-brush to remove all hair, dust, &c. Glair is now liberally applied with a thick hair brush, laying it on separately for each strip. The gold is now lifted from the cushion with the gilder's tip so that it very slightly projects over the end of the brush and is transferred to the wet edges. The tip is brought to within 1 cm. of the surface of the edges and with a quick motion the whole surface of the gold is at once brought into contact with the glaired edges, which will instantly take it up quite greedily. The gold slightly overlaps on to the inner boards. In this one continues, preparing the edge for each fresh strip and laying on each strip so that it slightly overlaps the other until the whole length is covered with gold. If the gold should be injured in any way, the press must be tilted so as to allow a little glair to run under the gold to the spot and then a larger piece is laid over the faulty place. When it is seen that all parts are completely covered, the press-jack is put aside, the press is taken by the screws between the beams and raised high overhead so that the gilded part is turned downwards. One end is carefully lowered until the glair has run to one side and dripped off. As soon as the greater part of the moisture has been removed, the press is either placed upright with the edge to the wall and head downwards or it is laid across the table where it will not be disturbed, with the head of one screw on the table edge. In this way the moisture runs off quicker, as the whole length of the edge drains together. When dry, the edges are burnished, and it is in seizing the right moment to do this that the clever finisher shows his skill. The first test is made on the boards. If the gold comes off on scratching the portion on the inner board with the finger-nail, the edge is still too damp; if the scratching makes it shine, it will be all right. The experienced worker can trace the progress of drying with more certainty by breathing on the edges; the slowness or rapidity with which the breath disappears points to the dry or moist state of the edges.
When it is believed that the proper degree of dryness has been obtained, the edge is polished with a burnisher. A piece of tracing paper which has been waxed on the upper side—that is, the side next the burnisher—is laid on the fresh edge to protect it from injury. The burnisher is then worked crosswise, stroke by stroke, over the paper (through which the edge can be observed) the length of the edge; if it is noticed that gold and moisture adhere to the paper near to the boards, the work must be laid aside to wait a little longer. If, however, the whole process has gone on satisfactorily, the edge is gone over with a linen rag and a little beeswax. It is not at all better to use a silk rag instead of linen, for it happens too easily that tiny threads stick to the gold unnoticed and are afterwards rubbed into the edge. After going over the edge with the waxed rag, the bare edges may take a greater pressure in burnishing, and if no flaws are now perceptible there need be no hesitation in burnishing with very strong pressure. The burnisher must be held quite level, the long handle fixed against the shoulder and the lower end firmly gripped with both hands just above the metal fastening. The fore-edge of the burnisher is not to be held parallel to the sheets, but must be at a slight angle; it thus slips better over the paper and there is less danger of making rills and furrows, and the polish is obtained more rapidly. Flat edges are always burnished crosswise, but at the end a broad burnisher may be used for going over the edges lengthwise with a few slow, firm strokes, so as to ensure a very level surface.