COPPER ENGRAVING is the earliest intaglio process. The image is engraved with a burin into a 2–4 mm thick copper plate. The burr is cleaned off with a scraper, and the plate is covered with printer's ink. As the plate is rubbed all over, the ink remains only in the grooves of the image. The image is then printed from the plate onto moistened paper by means of a printing press. In copper engraving, the image is conveyed by lines of various width and thickness as well as by triangular or rhombic dots. The line is characterized by its getting thinner at ends, which distinguishes it from the etching line. The copper engraving plate yields about 200 excellent, 600 good, and 800 medium quality prints.