Objects

intaglio (incised) in the metal.[14] In modern manufacturing, other chemicals may be used on other types of material. As a method of printmaking, it is, along with engraving, the most important technique for old master prints, and remains in wide use today. In a number of modern variants such as microfabrication etching and photochemical milling it is a crucial technique in much modern technology, including circuit boards. In traditional pure etching, a metal (usually copper, zinc or steel) plate is covered with a waxy ground which is resistant to acid.[15] The artist then scratches off the ground with a pointed etching needle[16] where he or she wants a line to appear in the finished piece, so exposing the bare metal. The échoppe, a tool with a slanted oval section, is also used for "swelling" lines.[17] The plate is then dipped in a bath of acid, technically called the mordant (French for "biting") or etchant, or has acid washed over it.[18] The acid "bites" into the metal (it converts metal into salt solution and hydrogen) to a depth depending on time and acid strength, leaving behind the drawing skillfully carved into the wax on the plate. The remaining ground is then cleaned off the plate. For first and renewed uses the plate is inked in any chosen non-corrosive ink all over and the surface ink drained and wiped clean, leaving ink in the etched forms." - (en.wikipedia.org 19.11.2019)