An engraving technique on a copper plate that has been worked with a tool called a rocker, a crescent-shaped instrument with sharp teeth on the curve of the crescent. The marks cover the entire plate, and are made with a rocking motion. Then the copper plate is burnished or smoothed in areas by the artist. When the mezzotint is made, only the scored areas retain the ink and create the design. The smooth areas are the non-colored part of the image. Gatja Rothe, working with Edward Weston, was especially noted for mezzotint. Source: "Joel Oppenheimer" 35th Anniversary Catalogue, 2004, of the Natural Art Gallery; (LPD)