ENGRAVING. The art of producing figures or designs upon metals, stone, wood, and various other substances, by means of lines cut upon the sur face. In this extensive sense of the term, the art is doubtless of very great antiquity, repeated mention being made in Scripture of seals, signets, and other works of the graver ; but the word usually signifies the art of producing designs as above for the purpose of being subsequently printed upon paper, which copies are also called engravings ; and in this sense of the term the art does not appear to have been known or practised in Europe until the middle of the fifteenth century. In the present day it is held in very great esteem, and is very extensively practised. It may be divided into two branches, according to the substances upon which the design is engraved, which is generally either metal or wood, although glass and other substances have been occasionally em ployed. Of the metals, copper has, until within these few years, been almost exclusively chosen for engraving, on account of its ductility, evenness of tex ture, and the softness and delicacy of the tints which may be produced upon it; but latterly, steel plates have been very extensively employed for this purpose, and although the engravings thus produced are perhaps somewhat inferior softness to those obtained from copper, a very high pitch of excellence has been attained, and in point of durability the copper-plates will bear no com parison with steel-plates. Engraving on copper is performed in various styles, the principal of which are line engraving, mezzotinto, etching, and aquatints.
Lane ' is considered as the highest department of the art, and is always employed in the illustration of historical subjects. In this style of engraving the lines are all cut upon the copper by means of an instrument called a graver, the roughness being removed by a • steel instrument called a scraper. To trace the design upon the plate (which for every style of engraving should be of the best copper well planished and burnished), it is usual to heat the plate sufficiently to melt white wax, with which it must be covered equally with a thin film, and then suffered to cool ; the drawing is copied in outline with a black lead pencil on paper, which is then laid with the pencilled side upon the wax, and the back rubbed gently with a burnisher, which will transfer the lead to the wax. The design is then traced with an
etching needle through the wax on the copper, when on wiping it clean it will exhibit all the outlines ready for the engraver.
Menvotinta Engraving differs entirely from the manner above described, and is chiefly employed for portraits and imitations of Indian ink drawings. The mode of proceeding is as follows :—the plate is prepared by scratching it equally in every direction with a tool called a grounding tool, so as to remove entirely the polish from the surface, which is thus converted into a chaos of intersections, which, if covered with ink and printed, would present a perfectly black impression upon the paper. To transfer the design to be scraped, it is usual to rub the rough side of the plate with a rag dipped into the scrapings of black chalk, or to smoke it with a burning wax taper, as in the process of etching. The back of the design is then covered with a mixture of powdered red chalk and flake white, and laid on the plate, and the outline of the design being lightly traced with a blunt point, the red particles at the back are thus transferred to the black ground of the plate in the form of a corresponding outline ; the process must then be carried on with a scraper, by restoring the plate in the perfectly light parts of the intended print to a smooth surface, from which the gradations are preserved by scraping off more or less of the rough ground, but the burnisher is necessary to polish the extreme edges of drapery, dm., when the free touch of the brush in painting represents a brilliant spot of light. The deepest shades are sometimes etched and corroded by aquafortie, and so blended with the mezzotinto ground added afterwards, that there is nothing offensive to the eye in the combination. Many proofs are required to ascertain whether the scraping approaches the desired effect, which is done by touching the deficient parts with 'white or black chalk on one of the proofs, and then endeavouring to make the plate similar by further scraping, or by relay ing the ground with a small tool made for this particular purpose, where too much of the roughness has been effaced.