Etching
2 of the 6 encyclopedias on this shelf carry an entry for Etching. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
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
Collier's New Encyclopedia (1921)
the art of producing designs on a plate of steel or copper by means of lines drawn with an etching needle. See ENGRAVING.
What Has Changed in the Last Century
An etcher today would recognize almost every step Aiton's described in 1910: the polished plate, the waxy ground smoked brown, the needle, the acid bath, the stopping-out varnish, the ink wiped from the surface and the raised ridge of ink you can feel with a fingertip. What has changed most is the chemistry, as studios from the 1990s onward moved away from nitric acid and asphaltum grounds toward safer ferric chloride or copper-sulphate mordants and acrylic-based grounds, with ventilation rules that would have startled a printer content with rubber gloves and a shallow basin. The commercial reason for etching has also vanished: by the time Collier's wrote in 1921 photomechanical processes were already taking over illustration, and the etching print boom collapsed in the 1929 crash, leaving the medium as a fine-art practice rather than a trade. The word itself has meanwhile acquired a far larger industrial life in the chemical and plasma etching of silicon wafers for computer chips. Aiton's verdict that Rembrandt remains unsurpassed is still the common one.
Written for this edition, 2026.