An early technique in copperplate engraving, invented in the seventeenth century by Ludwig von Siegen, which involves etching a copper or steel printing plate with a pattern of cross-hatched lines or dots to provide the illusion of continuous tone images and gray values. The denser the pattern of lines or dots, the darker the tone. The mezzotint process eventally gave birth to halftone photography. In fact, the word mezzotint itself means, in Italian, "halftone." Mezzotinting is still used in design and illustration primarily as a special effect.