Preparatory to gilding, the back must be compassed off and carefully marked with a folding-stick and a straight-edge or piece of vellum, wherever it is intended to run a straight line. This serves as a guide when the gold is laid on. For work of the best class, the fillets must be first put in blind, and the tooling done in the same manner. For sides where the design is elaborate, or a degree of perfection in the tooling is desirable, the entire pattern must be first worked in blind, and, after being washed with a dilution of oxalic acid or a thin paste-wash, it must be carefully pencilled in with the glaire-pencil; but this comes more appropriately under the head of
PREPARATIONS FOR GILDING.
To operate successfully, it will be necessary that the workman provide himself with good size, glaire, and oil. The first is prepared by boiling fine vellum slips till a good size is produced, of a consistency that will lie equally on the volume without blotches or ropes, and must be used warm. The glaire is formed of the whites of eggs, beaten well with a frother till it is perfectly clear, and the froth taken off. This liquid will improve by keeping, and should never be used new if it can possibly be avoided. For morocco bindings, the glaire is sometimes diluted with water. The oil adopted by various binders is different. Some use palm-oil for calf, sweet oil for morocco or russia; others prefer hog's lard, or fine mould-candle, for light-coloured calf; but sweet oil is well adapted for almost every kind of leather. Vellum-size is the best preparation for coloured calf. On books thus prepared, the glaire must be applied two or three times, taking care that each coat is quite dry before the next is added, and that it lies perfectly even on the whole surface, free from globules or any substance whatever. Great care is required in preparing coloured calf; for, if there be too much body in the preparation, it will crack on the surface and present a bad appearance. Morocco and roan will not require more than one coat, and, where practicable, only on such parts of the morocco as are to be gilt. The state of the weather must ever determine the number of volumes to be proceeded with at one time, as in the winter double the number may be glaired to what the dryness of a summer's day will admit of, so as to work with safety and produce effect. A good paste-wash before glairing is always advisable, as it prevents the glaire from sinking into the leather.
In preparing glaire from the egg for immediate use, a few drops of oxalic acid added thereunto will be found to be of essential service.
The volumes being thus prepared, the operation of
GILDING THE BACK
Is commenced by oiling slightly, with a small piece of cotton, the whole length of the back. If the book is merely intended to be filleted for the economy of the gold, small strips are cut on the gold-cushion, attached to the heated fillet by rolling it slightly over, and affixed to the volume by passing it firmly on the lines previously marked. But if the back is to be fully ornamented, it will be necessary to cover it entirely with gold-leaf.
The hand-stamps should be disposed on the table before him, so as to be selected with the greatest facility, and in readiness for every purpose for which they may be required.
To lay on the gold, the workman takes a book of the metal, opens the outside leaf, and passes the knife underneath the gold; with this he raises it, carries it steadily on to the cushion, and spreads it perfectly even, by a light breath on the middle of the leaf, taking care also that not the least current of air has access to the room he may be operating in. Afterwards the gold must be cut with the gold-knife to the breadth and length of the places to be covered, by laying the edge upon it and moving the knife slightly backwards and forwards. Then rub upon the back the oil, and apply the gold upon the places to be ornamented with a cotton or tip, rubbed on the forehead or hair to give it a slight humidity and cause the gold to adhere. But if the whole of the back is to be gilt, it will be more economical to entirely cover it by cutting the gold in slips the breadth of the book and applying the back on it; afterwards press it close with the cotton, with which any breaks in the gold must also be covered, by placing small slips where required. The humidity of the hair or forehead will be sufficient to make the gold adhere to the cotton or other instrument with which it may be conveyed to the book. The fillet or roll must then be heated to a degree proper for the substance on which it is to be worked. Calf will require them hotter than morocco and roan, and these warmer than russia and vellum. To ascertain their proper heat, they are applied on a damp sponge, or rubbed with the finger wetted, and by the degree of boiling that the water makes, their fitness is known; but a little exercise and habit will render this easy of judging. To further insure this, the roll or pallet is passed over the cap of the headband; if too hot, the gold will be dull; if too cool, the impression will be bad, from the gold not adhering in every part.
After the gold is laid on, the volume is laid upon the side, with the back elevated, and the workman proceeds to mitre the fillets that run lengthwise of the back, commencing at the line that has been traced across the back, by pressing lightly with the point of the mitred roll and running it carefully till near the line that marks the end of the panel; then lift the fillet and turn it with the finger until the other or reverse mitre, or nick in the fillet, is reached; then place the fillet in the lines already gilt, adjusting it with the left hand until the extreme point of the mitre will just reach the line traced across. After both edges of the back have been done along the joint in this way, the volume is then placed evenly in the finishing-press, and the panels completed by mitreing the fillets that run across the back. The entire operation requires the utmost care, in order to have the lines parallel and the mitres perfectly even and true. No ornament that may be afterwards worked upon the back, beautiful as it may be, can atone for negligence or want of skill in the mitreing and running of the fillets. As a matter of economy, sometimes the back is run up; that is, instead of stopping where the lines or bands intersect, the roll is run up the back from one end to the other, without stopping; and, after wiping the gold off along the joint outside the fillet, it is run across the back on each side of the bands, and head and tail in the same manner. After the back is mitred, the finisher will proceed with the ornamental tools, and work them carefully off. In placing them, great attention should be paid to their occupying precisely the same place in each panel; and, in order to present an agreeable effect, the tools should correspond in detail, and there should be a geometrical fitness governing the selection and arrangement of the tools.