Making an Etching
Making an Etching
Etching is simply a process of printing in intaglio. That is, instead of a method for taking an impression on paper from a series of raised lines, etching is a form of engraving in which lines are eaten into a flat surface, these depressions being filled with ink and the ink then transferred to paper under pressure.
The flat surface on which the drawing is made is a polished metal plate, and the manner in which the lines or grooves are sunk into the surface of the plate determines the nature of the subsequent print.
In making an engraving the artist uses a burin, a sharp steel instrument, which acts like a little plough, digging clean grooves into the metal plate.
In the dry-point the instrument used is a steel or diamond point. This method allows more freedom than the burin and the lines are therefore more spontaneous and elastic. The distinguishing feature of dry-point is the burr thrown up by the needle, on both sides of the furrow if held perpendicularly, and on only one side if held at a slant. Dry-point is very often used in conjunction with etching, adding the finishing touches to a plate.
The etching proper differs from the engraving or dry-point in that the furrows or lines are not cut into the plate by main force, but are the result of chemical action. A copper penny dropped into a tray of nitric acid disappears in a few minutes--dissolved by the acid just as sugar is dissolved by water. But if the coin were coated in wax or resin before being placed in the acid, nothing would happen, since nitric acid does not eat into wax. It is on this principle that all etching is based. Specifically, a copper plate is covered with a protective substance, or "ground," into which the design is scratched with a sharp needle. The plate is then put into a bath of nitric acid. Since the acid can only act on the copper in places where it is unprotected, the design that has been scratched through the wax is etched, or "bitten," into the plate. The longer the plate is left in the acid the deeper the . . .