The Etching Process
In pure etching, a metal (usually copper, zinc or steel) plate is covered with
a waxy ground which is resistant to acid. The artist then scratches off the ground with a pointed etching needle where he
wants a line to appear in the finished piece, so exposing the bare metal. The plate is then dipped in a bath of acid,
technically called the mordant (from the French for "bite"), or has acid washed over
it. The acid "bites" into the metal, where it is exposed, leaving behind lines sunk into the plate. The remaining
ground is then cleaned off the plate. The plate is inked all over, and then the ink wiped off the surface, leaving only the
ink in the etched lines.
The plate is then put through a high-pressure
printing press together with a sheet of paper (often moistened to soften
it). The paper picks up the ink from the etched lines, making a print. The process can be repeated many times.
Etching by goldsmiths and other metal-workers in order
to decorate metal items such as guns, armour, cups and plates has been known in Europe since at least the Middle Ages. The process as applied to printmaking is believed to have been invented by Daniel Hopfer
(circa 1470-1536) of Augsburg, Germany. Hopfer was a craftsman who decorated armour
in this way, and applied the method to printmaking, using iron plates. The switch to copper plates
was probably made in Italy in the mid to late 1500's. Etching soon came to challenge engraving as
the most popular medium for artists in printmaking. Its great advantage was that, unlike engraving which
requires special skill in metalworking, etching is more accessible for an artist skilled in drawing.