Etching

As with copper engraving etching is a gravure printing process. First, the metal plate (for example copper, brass or zinc) receives an acid-resistant coating, the etching base. This is applied with a brush. It has the appropriate consistency as long as the copper of the printing plate is still visible. [1]

The desired drawing is then carved with the aid of a tool, the etching needle, mirror inverted into the coating of the printing plate. This is followed by a bath in acid. The etching base protects the plate so that no acid penetrates except for the scribed areas where the coating has been removed. The lines of the drawing itself are attacked and thus deepened. Then they are able to pick up the ink.

After the acid bath, the etching base is removed again and the printing ink is applied to the plate by means of a bale. The color sets in the incised depressions. Before printing is possible, the metal plate is wiped off so that excess paint is removed. [2]

The printing takes place in a roller press by covering the plate, which now contains the printing ink, with a moistened and therefore absorbent paper and a felt. The paper is pressed into the wells, where it can absorb the color, which then noticeably rests as soon as the finished print has been removed from the press.

The edge of the plate is present as a characteristic feature of all low pressure techniques also in etching. The etching allows for a lighter and thus more fluid line compared to the copper engraving, since the plate itself is not injured by needle in form of chip removal, as is the case by using a graver. Instead, the acid replaces the work process by penetration and etching, which otherwise would have to be done by hand and requires a corresponding amount of force. [1]

In addition to the German artist Albrecht Dürer (1471 - 1528), the etching was also practiced by the Swiss-German engraver Matthäus Merian (1593-1650). [3]

References

[1] Etching (German):
https://de.wikipedia.org/wiki/Radierung
[2] Zender, Joachim Elias: Lexikon Buch, Druck, Papier, 2008.
[3] Matthäus Merian (German):
https://de.wikipedia.org/wiki/Matth%C3%A4us_Merian