From Latin radere (scratch, grate). Second most used gravure printing technique besides the copper engraving. A smooth and burnished copper or zinc plate is covered with an acid-resistant varnish called etching ground. The drawing is now applied onto the plate either directly or by use of carbon paper and afterwards scratched into the plates surface with a needle, thus removing the varnish. The plate is then cauterised and the uncovered areas become recesses. After the etching ground has been removed, the plate is dipped in ink and cleaned with the ink only remaining in the recesses. During printing, the ink is transferred onto the paper. Etchings and copper engraving differ in the appearance of their lines. Whereas lines in copper engravings are of different width and taper towards the end, etching features even lines of uniform width.