What is an etching?

Etching is one method of printmaking that has been used by artists since the 15th century.  In simple terms it involves the artist scratching on to a metal plate (typically copper, steel or zinc) with a needle to create an image.  The plate is then dipped into acid which results in lines being sunk into the plate.  The plate is then covered in ink which is wiped off leaving ink just in the scratched lines.  Paper is then placed on the plate and pressed down.    The resulting image on the paper is an etching!  Naturally there are variations in this process.

A few examples of artists who used this technique include Rembrandt, Jaques Callot, Pablo Picasso and Antony Gormley.  Here are some example etchings: