ENAMELLING, the art of laying enamel upon metals, as gold, silver, or copper, and of melting it on the fire, or of making divers curious works in it by means of a lamp. It signifies also to paint in enamel.

The method of painting in Εnαmεl. This is performed on plates of gold or silver, and most commonly of copper, [7:8:694]enamelled with the white enamel, on which painting is executed with colours which are melted in the fire, where they take a brightness and lustre like that of glass. This painting is the most prized of all for its peculiar brightness and vivacity, which is permanent, the force of its colours not being liable to be effaced or sullied with time, as in other painting, and continuing always as fresh as when it came out of the workmen’s hands. This method of painting is usual in miniature; but it is the more difficult the larger it is, by reason of certain accidents to which it is liable in the operation. Enamelling should only be practised on plates of gold, the other metals being less pure; copper, for instance, scales with the application, and yields fumes, and silver turns the yellow white. Nor must the plate be made flat; for in such case the enamel cracks; to avoid which accident the plates are usually forged a little round or oval, and not too thick. The plate being well and evenly forged, the operation is usually commenced by laying on a couch of white enamel (as we observed above) on both sides, which prevents the metal from swelling and blistering; and this first layer serves for the ground of all the other colours. The plate being thus prepared, the next step is to draw out exactly the subject to be painted with red vitriol, mixed with oil of spike, marking all parts of the design very lightly with a small pencil. After this, the colours (which must be previously ground with water in a mortar of agate extremely fine, and mixed with oil of spike somewhat thick) are to be laid on, observing the mixtures and colours which agree to the different parts of the subject; for which purpose it is necessary to understand painting in miniature. But here the workmen must be very cautious as to the quality of the oil of spike he employs to mix his colours with, for it is very subject to adulteration.

Great care must likewise be taken that the least dust imaginable mix not with the colours while the artist is either painting or grinding them; for the smallest speck worked up with the colour, when the work comes to be put into the reverberatory to be made red hot, will leave a hole, and so deface the performance.

When the colours are all laid, the painting must be gently dried over a slow fire to evaporate the oil, and the colours afterwards melted to incorporate them with the enamel, making the plate red hot in a fire like that which the enamellers use. Afterwards that part of the painting must be gone over again which the fire has in any degree effaced,
strenghening
the shade and colours, and committing it a second time to the fire, observing the same method as before, which is to be repeated till the work be finished.

Method of Enamelling by the lamp. Most enamelled works are wrought at the fire of a lamp, in which, instead of oil, is put melted horse-grease, which they called caballine oil. The lamp, which is of copper, or white iron, consists of two pieces; in one of which is a kind of oval plate, six inches long and two inches high, in which are put the oil and the cotton; whilst the other part, called the box, in which the lamp is inclosed, serves only to receive the oil which boils over by the force of the fire. This lamp, or, where several artists work together, two or more lamps, are placed on a table of proper height, under which, about the middle of its height, is a double pair of organ-bellows, which one of the workmen moves up and down with his foot to quicken the flame of the lamps, which by this means is excited to an incredible degree of vehemence. Grooves made with a gauge in the upper part of the table, and covered with parchment, convey the wind of the bellows to a pipe of glass before each lamp; and in order that the enamellers may not be incommoded with the heat of the lamp, every pipe is covered at six inches instance with a little tin plate, fixed into the table by a wooden .handle. When the works do not require a long blast, the workmen only use a glass pipe, into which they blow with their mouth.

It is incredible to what a degree of fineness and delicacy the threads of enamel may be drawn at the lamp. Those which are used in making false tufts of feathers are so fine that they may be wound on a reel like silk or thread. The fictitious jets of all colours used in embroideries are also made of enamel, and that with so much art, that every small piece has its hole to pass the thread through with which it is sewed. These holes are made by blowing them into long pieces, which are afterwards cut with a proper tool.

It is seldom that the Venetian or Dutch enamels are used alone; they are commonly melted in an iron ladle, with an equal part of glass or crystal; and when the two matters are in perfect fusion, the mass is drawn out into threads of different sizes, according to the nature of the work. The workmen take it out of the ladle while liquid with two pieces of broken tobacco-pipes, which they extend from each other at arm’s length. If the thread is required still longer, then another workman holds one end, and continues to draw it out, while the first holds the enamel to the flame. Those threads, when cold, are cut into whatever lengths the workman thinks fit, but commonly from ten to twelve inches; and as they are all round, if they are required to be flat, they must, while hot, be drawn through a pair of pincers. They have also another iron instrument in the form of pincers for drawing out the enamel by the lamp when it is to be worked and disposed in figures. Lastly, they have glass tubes of various sizes, which serve to blow the enamel into various figures, and preserve the necessary vacancies therein, as also to spare the stuff, and form the contours. When the enameller is at work, he sits before the lamp with his foot on the step which moves the bellows; and holding in his left hand the work to be enamelled, or the brass or iron wires on which the figures are to be formed, he directs with his right the enamel thread, which he holds to the flame with a management and patience equally surprising. There are few things which cannot be made or represented with enamel; and some figures are as well finished as if done by the most skilful carvers.