Engraving

Engraving is the practice of incising a design onto a hard, flat surface, by cuttinggrooves into it. The result may be a decorative object in itself, as when silver or gold are engraved, or in art may provide an intaglio printing plate in printmaking, of copper or another metal.
In the European Middle Ages goldsmiths used engraving to decorate and inscribe metalwork. It is thought that they began to print impressions of their designs to record them. From this grew the engraving of copper printing plates to produce artisticimages on paper, known as old master prints in Germany in the 1430s. Italy soon followed. Many early engravers came from a goldsmithing background. The first and greatest period of the engraving was from about 1470 to 1530, with such masters as Martin Schongauer , Albrecht Dürer , and Lucas van Leiden.
Because of the high level of microscopic detail that can be achieved by a master engraver, counterfeiting of engraved designs is well-nigh impossible, and modern banknotes are almost always engraved. Many classic postage stamps were engraved, although the practice is now mostly confined to particular countries, and/or used when a more "elegant" design is desired and a limited color range is acceptable. (From wikipedia.org)