MEZZOTINT or MEZZO TINTO, as it was first called, is a process of engraving whereby a copper, or steel, plate is first prepared to produce uniformly black impressions on paper. This is done by pricking the plate with innumerable small holes which will hold ink. In connection with mezzotint, as with all other forms of engraving, the ink used is a thick ink which does not run. After the surface of the mezzotint plate has been pre pared, the high lights in the portrait or picture to be produced are obtained by scraping away and burnishing parts of the plate, thus reducing, or obliterating, the small holes, accord ing to the effect desired. The pricking of the plate, originally done with a roulette or small wheel covered with sharp points, was later done with an instrument called a cradle, or rocker. The process not only punctures the plate to hold ink, but, at the same time, produces a burr on the surface of the metal, which, cutting into the paper when in the press, causes a deeper absorption of ink, and produces that velvety effect so characteristic of the fine mezzotint engraving in an early impression. The surface of the punctured and roughened plate is left undisturbed where the deepest black is required, and by a graduated scraping of the plate, which removes both burrs and punctures so that ink is held in lesser degrees, middle and light tones are obtained when an impression is taken from it. Dots made with a sharp point on a polished metal surface were long used as an adjunct to engrav ings. They show on silver plates engraved for Niello (q.v.) in the 14th century. Prints on paper from line engravings cut on metal plates, probably copper, were first made about the middle of the 15th century, but dotted, or pointille work does not seem to have been much used for some time after that.
The 17th Century Dutch School.—About the middle of the I7th century, Ludwig von Siegen, a Dutch officer in the Hessian army, who was also an amateur artist, applied the old device of dotted work to a metal plate, by means of a small roulette, and succeeded in producing an excellent print entirely by its use. In
1654, von Siegen met Prince Rupert, count palatine of the Rhine and grandson of James I., at Brussels. Prince Rupert was a skilled amateur artist, and he became deeply interested in von Siegen's invention, which he at once tried. In a short time he produced a very fine piece of rouletting in a print of The Large Executioner, after Spagnoletto, a Spanish painter. The curving lines, made by unskilful use of a large roulette, show clearly in the background. William Sherwin was a native of Hertfordshire, and a well known line engraver. He was also a friend of Prince Rupert, who is said to have taught him the new art and pre sented him with a roulette. Sherwin made mezzotint portraits of Charles II. and of his queen in 1669, both of which were dedicated to Prince Rupert.
The early mezzotinters were mostly Dutchmen, and they did not succeed particularly well. Curiously enough, most of their work was done in England. But eventually, a great Dutch artist, Abraham Blooteling, arrived in England in 1673, and was much attracted by the new art. Blooteling did much splendid work, particularly after Van Dyck, Kneller and Lely. But he did much more for the art of the mezzotint than produce beautiful prints, because he radically changed and improved the technical part of the process. Instead of using only a roulette to produce dark space, he began by roughening the plate all over, so that if printed from, it would show simply a black space, and then he cut away the roughness with a scraper to make the light places as required. This plan produced most brilliant effects. Blooteling also in vented a tool, now called a rocker, which is like a very small spade with a toothed edge, and with this powerful instrument a copper or soft steel plate can quickly be roughened all over, rendering the use of the old roulette obsolete. The early users of the rocker roughened their own plates, but now this can be pro fessionally done by the dealers.