etcher

[Eng.etch (1); -er.] One who etches, "The etcher does not reproduce nature, he translates it into a language of his own." London Times. ětch-ing, pr. par., a. & 8. [ETCH (1), v.] A. & B. As pr. par . & particip . adj .: (See the verb.) C. As substantive: 1. On metal: Engraving executed by a pointed tool and acid upon a prepared metallic surface previously covered with varnish. The ordinary procedure is as follows: Cover a polished metallic plate with a composition technically called ground, and consisting of asphaltum, four parts; Burgundy pitch, two parts; white wax, one part. For use this is melted and compounded, and tied up in a silk rag. The plate is heated, rubbed with the which is then spread smoked, drain dry. The parts having sufficient depth are now stopped out by a varnish of Brunswick-black. When the varnish is dry, another biting-in will deepen the lines of the parts not stopped out, and when these lines are deep enough for the second tint, the varnish is removed, the plate dried, . This is repeated as many times as may be neces sary. The wall of wax is then removed, the surface of the plate cleaned with turpentine, and a proof taken. It may be finished by a graver, but then partakes of the character of a line engraving. Another mode of etching is to remove lights with point and scraper, and then bite-in so as to expose the design in relief. 2. On gla : This art was invented by Schwanhard of Nuremberg, 1670, and originated in an accident to his spectacles, which became corroded by some drops of acid. Fluoric acid, discovered by Scheele, 1771, is now employed for biting-in the etching. The gla is covered with a resinous ground, and the design marked by an etching point, exposing the gla . The latter is then subjected to an acid, which acts upon the silicate and eats away the gla at these points, making depre ions which constitute the etching. 3. On soft ground : An imitation of chalk or pencil drawing, which has been abandoned since lithography has attained excellence. The soft ground is made by adding one part of hog's lard to three parts etching ground [GROUND], which is laid on the plate with the dabber in the usual way. A piece of smooth writing-paper, having the design in outline, is damped and stretched over the plate. A pencil is then used to follow the lines of the design mob serving that the softer the ground the softer the pencil should be. The temperature of the season or the room will affect the character of the ground. When the paper is removed it withdraws the adhering lines of ground, and the plate is bitten-in in the usual way. IMG:content-1157.png:[blocks in formation] (b) The surface of the stone is covered with an asphaltum ground; the work is etched in, cutting away so much of the ground and exposing the stone. Acid is then applied, which eats away the stone, making a depre ion; this is inked, the asphaltum cleaned off, the clear spaces etched and gummed as usual in the lithographic proce . 5. An impre ion taken from an etched plate. etching-figure s, s . pl . Mineralogy: Figures or markings indented on crystals by the action of appropriate solvents. Their form is usually definite, and they are considered important as revealing the very small, invisible particles of which all matter is supposed to consist.