INLAYING, a method of ornamentation by inserting in one material a substance differing therefrom in colour or composition. The art is practised in the fabrication of furniture and artistic objects in all varieties of wood, metal, shell, ivory, coloured and hard stone, and in compound substances. Forms of inlay include: Niello (q.v.), is an ancient and much-practised method of inlay ing silver and gold with various metals.
Demascening is the inlaying of gold wire in iron or steel.
Mosaic (q.v.) is generally applied to inlay work in hard stone, marble and glass, but the most important class of mosaics—those which consist of innumerable small separate pieces—do not prop erly come under the head of inlaying.
Pietra dura is a fine variety of inlaid mosaic in which hard and expensive stones—agate, cornelian, amethyst and the like—are used in relief.
Intarsia was originally a true inlay of one or more colours of wood upon a darker or lighter ground, and it is from this form of inlaying that marquetry and other wood inlays were developed.
Inlay and Marquetry.—Inlay is more often confined to woodwork, and the art of decorating the surfaces of furniture or wall panelling with small pieces of wood, ivory, tortoise-shell, etc., that are cut into various designs and set into the body of the surface. The term "inlay" is often confused with and some times used for the word "marquetry." Marquetry is composed of pieces of very thin wood, or other material of equal thickness, laid down upon a matrix with glue. Thus marquetry is a veneer process, while true inlay is what the term implies—"a laying in" of one material into another material called the "ground." Mar quetry is a later development of the ornamental inlays of wood known by the name of Intarsia, which, although a true inlay as opposed to the thin veneer of marquetry, furnishes many exam ples wherein the process follows that of marquetry. For example in the cathedral of Ferrara, Italy, the backs of the stalls show the perspective lines of some of the subjects traced upon the ground where the marquetry has fallen off, but none of the "sinkings" would be there if the panels had been executed as true inlays instead of veneers.
Process.—The design for a panel is drawn on paper, the lines being pricked through to underlying sheets to make the necessary number of copies, or the pricked sheet is dusted over with a coloured powder which passes through the perforations and marks the design faintly on the paper underneath. The pieces of paper are then cut up and stuck on to several pieces of wood which form the design, one whole print being reserved to paste complete on to the ground or field. Each piece may be cut separately, but they are all bound to fit into the complete pattern when this is cut out of the ground, because all are cut from the same prints. In true inlay the pieces to be inserted are cut out of wood to a in. thick. The surface into which these separate designs are to be set is carved out the required depth with wood-carver's tools, and the pieces making the design are driven in.
In marquetry two panels are sometimes made of the reverse colourings by sawing through the ground and the veneer at the same time. At one time it was quite a common occurrence to produce two pieces of furniture in which one was brass inlaid in the black, and in the other case the pattern was black inlaid in the brass, thus utilizing what would otherwise have been very costly waste material. Although this method of cutting through two or more pieces of wood clamped together, and simply drop ping one piece into the opening made by the other, is not generally considered as fine work, many excellent inlayers like Boulle in the time of Louis XIV., did their inlay work, or marquetry, in just that way. When all the parts have been cut and fitted together face downwards, paper is glued over them to keep them in place, and the ground and the veneer are carefully levelled. The ground is then wetted with glue at a high temperature and the surfaces squeezed between the frames called "cauls" until the glue is hard.
History and Development.—Probably the earliest examples of inlay were found in the Venetian work of the i4th century, when wood was inlaid on ivory boxes. Other materials were used at an early date. One of the most beautiful forms of inlay ex ecuted by the Italians was with ivory upon walnut wood or black wood. In the i6th century the Italians made inlays of marble in various colours, and in the 17th century a combination of tortoise shell and metal was not uncommon.
Most of the examples found in England are importations, either from Holland or France. The reputation of the Dutch mar queteurs was so great that Colbert engaged two, Pierre Gale and Vordt, for the Gobelins at the beginning of the 17th century. Jean Mace of Blois, the first Frenchman known to have prac tised the art, who was at work in Paris from 1644 (when he was lodged in the Louvre) or earlier, till 1672, as a sculptor and painter, learned marquetry in the Netherlands. His daughter married Pierre Boulle, and the greatest of the family, Andre Charles Boulle, succeeded to his lodging in the Louvre on his death in 1672. The members of this family are perhaps the best known of the French marqueteurs. Their greatest triumphs were gained in the marquetry of metal and tortoise-shell combined with beautifully chiselled ormolu mountings. It is thought by many that Boulle carried the work of inlaying too far. The i8th century commode of late Louis XIV. period, of tortoise-shell, mother-of-pearl and coloured ivories inlaid in brass, an example of which may be seen at South Kensington, is characteristic.
The Stuart period produced a good deal of marquetry in Eng land, often pieces of real excellence. Long-case clocks, cabinets, chests of drawers and various other pieces of furniture were sub jected to this kind of decoration. A shallower form of marquetry and some solid inlay work were also extensively used in the latter part of the 18th century. With the increase in luxury and display in the 17th and 18th centuries in France and Germany, cabinets and desks became objects upon which extraordinary talent and expenditure were lavished. Perhaps the most beautiful examples of the art in Italy are the panels of choir stalls or sacristy cup boards, though marriage coffers were also often sumptuously decorated in this manner. (F. L. D.)