Very useful models, both on a small scale for book illumination, and on an enlarged one for wall decoration, are now prepared by several of the artists' colour-men, for teaching amateurs the different modes of shading, &c. They consist of outline plates partially coloured by hand. The beginner will find it a very useful exercise to complete a few of these before trying his hand upon more original works upon vellum. The greatest care must be taken to have every implement perfectly clean. Experience alone can teach the artist the value of what are called glazing or transparent colours, such as the lakes, carmine, madders, gamboge, &c. Some tints may be used either as glazing colours, or as body-tints, according to their preparation, and according to the degree of thickness with which they are applied. As a general principle, all shades should be painted in transparent colour, all lights in opaque. Reflected lights may often be best given by scumbling thin body-colour over transparent shade. In order to prepare the tints for these operations, it may be well to use a little of Newman's or Miller's preparations with them. The less tints are retouched after the first application, the more clear and brilliant they are likely to remain. Above all things never let the paint-brush go near the mouth, and never attempt to correct or retouch a tint while it is in process of drying, as doing so will infallibly make it look streaky and muddy. In all these processes of manipulation, however, practice, good example, and good tuition, must teach what the minutest directions would fail to satisfactorily convey. The principal colours having been applied, the next difficulty will be to heighten them with gold and silver. Any large surfaces of gilding it will be well to apply previously to commencing colouring, and as much as possible intended for burnishing.
The principal metallic preparations used in illumination may be enumerated as follows:—gold leaf, gold paper, shell gold, saucer gold, gold paint, silver leaf, shell silver, and shell aluminium. Of these, the leaves, paper, and paint, are of English, and the shells and saucers of French manufacture. Occasionally gold and silver powder and German-metal leaf are employed, though too rarely to make them important enough to claim general notice.
The first-mentioned preparation of gold—gold-leaf—is the pure metal beaten into very thin leaves, generally 3⅛ inches, 3¼ inches, or 3⅜ inches square; but for illuminating purposes it should be still smaller—say 2½ inches square, as it is easier to handle than a larger size. For the same reason it is better to have the leaf double as thick as it is usually beaten. Gold leaf is sold in "books," each of which contains twenty-five gold "leaves," and for ordinary and general purposes, it is by far the best and most useful metallic preparation; but the difficulty of handling and laying it on deters amateurs from employing it, and it is difficult in writing to furnish a practical description of the modus operandi. The following is the usual mode:—
"Carefully open the book of gold, and if in so doing you disturb the leaf, gently blow it down flat again. If a whole leaf be required, take a rounded 'tip,' and quietly so place it on the leaf that the top of the tip be close to the edge of the leaf. In so doing, the sides of the tip will be brought down upon the side edges of the leaf, which then can be securely taken up and placed where required. If a small piece of gold leaf only be wanted, cautiously take up a leaf from the book by passing a 'gilder's knife' underneath, and place it on a 'gilders cushion;'[[118]] lay it flat with the knife, with which then cut the piece of the size required. If when you have laid gold leaf down with the tip it be wrinkly, blow it down flat."
The "gilder's tip" spoken of in the above extract is a very thin camel-hair brush, and for unskilled hands a semicircular tip is to be preferred to one of the ordinary form; as with it a leaf of gold may be firmly laid hold of, balanced, adjusted, and placed, without needing any particular knack. For long narrow pieces of gold, the ordinary gilder's tip is probably the best.
Gold paper consists of leaves of gold placed upon thin paper, a sheet of which, measuring about 19 inches by 12¾ inches, requires one book of gold. The mat or dead gold is most frequently used in illumination; but, when required, the bright or burnished gold can be procured. Gold paper is usually plain at the back, and when used, is required to be gummed on to the work; but it is far better to have it prepared on the back with a mixture of clear glue, sugar, &c., which can be laid on evenly and thickly, and yet is very strong. Paper thus prepared needs only to have a wet flat camel-hair brush passed over the back; it can then be laid down, and will adhere very firmly. In laying down gold paper, it is well to place a piece of white glazed paper on its face, then firmly to pass over it the edge of a flat rule or burnisher, in order to press down all inequalities and render the surface perfectly smooth.
Shell gold is gold powder mixed up and placed in mussel-shells for use. It is removed from the shell by the application of water, like moist colours, and is adapted for small work and fine lines, in which latter case a quill or reed pen will be found useful. When the work is dry, the gold can be brightened with a burnisher. Saucer gold only differs from shell gold in being placed in china saucers instead of shells.
Gold paint is a preparation of bronze in imitation of gold, and is usually sold in two bottles, one of powder and the other of liquid; which two ingredients, when mixed together, form the "paint," the use of which I do not recommend, as in course of time it turns black. The same objection unfortunately applies more or less, also, to the preparations of silver, which, however, are still occasionally used in illumination.
Silver leaf is made in the same manner as gold leaf, and the remarks made in reference to that are generally applicable to silver leaf.
Shell silver is not really silver, but an amalgam of tin and mercury prepared and placed in mussel-shells, and used with water in the same way as gold shells.