Etching

a method of picture making; also a picture produced by this method. Strictly speaking, a plate of metal is etched and the picture is printed from the etched plate. Etching differs from engraving. In the latter the lines are formed by a steel tool held in the hand of the engraver. In etching, the lines are etched or bitten out by the action of an acid. The etcher uses a thin plate of metal. It must have a highly polished surface. For a picture requiring broad, black lines, zinc is preferred; for fine, delicate lines copper is superior. Both copper and zinc are readily eaten or bitten by an acid. The artist first prepares his plate by warming the surface and rubbing it with a silk bag containing a delicate sort of asphalt. In this way he coats the entire plate with a varnish that nitric acid cannot attack. As this varnish is transparent, it is smoked to turn it brown, a color that shows lines well.

The artist then draws the desired picture on the varnished surface with a fine steel tool called a needle. The point of the needle removes the varnish wherever it passes. Care is taken not to scratch the metal. As the point of the needle plays easily on the waxed surface, the artist is as free as though using a pencil or pen on a sheet of paper. When his drawing is complete the etcher puts on a pair of rubber gloves and immerses his plate in a shallow basin of weak nitric acid. The acid bites or etches lines in the metal where the needle of the artist has removed the protecting varnish or wax. As soon as the etcher thinks the most delicate lines, as, for instance, sky lines, are bitten deep enough, he removes the plate from the bath and protects such portions by a coating of varnish--stopping out, this is called--and returns the plate to the acid. By the use of stopping-out varnish, as many degrees of delicacy and emphasis as may be desirable may be had. The advantage of both heavy and light lines is secured in this way.

When the etching is completed, the varnish is removed by washing in turpentine. The plate is then fastened on a wooden block or back. The printer planes off a shaving or pastes on paper as may be needed to give the exact thickness required for printing. Not infrequently the lines do not print well, and it is necessary to return the plate with a proof to the etcher for correction.

In printing, the etched lines are filled with ink and the rest of the surface is wiped off. By leaving slight traces of ink on the surface, fine, soft tints are obtained, giving the etching a rich, mellow effect. The furrows of an etched plate are hollowed out usually by the burrowing of the acid under the edges of the lines, giving a greater capacity for holding ink than if they were made by a tool. One who is skilled can tell an etching by passing his finger tip over the paper. The lines form little ridges of ink quite perceptible to the touch, and quite different from the lines of a woodcut or ordinary letters which create depressions instead of ridges.

Skillful etching requires not only a creative and artistic mind, but a skillful eye and hand. Of noted etchers, the artist Rembrandt is yet considered unsurpassed.

See Engraving