Shading. Engraving lines on a metallic surface to indicate texture or color. The width of the lines and their spacing is critical to effect the shaded appearance. Shading in the field of a numismatic or medallic item is termed texture. The direction of the shaded lines indicate color in heraldic design: vertical lines indicate red, horizontal blue, descending diagonal green, ascending diagonal purple and crosshatch indicates black. These are called tinctures in blazoning (describing coats of arms). Shading is a widely used technique of copperplate or banknote flat engraving, adopted somewhat to die engraving. See heraldry.
excerpted with permission from
For Artists, Makers, Collectors and Curators
COMPILED AND WRITTEN BY D. WAYNE JOHNSON
Roger W. Burdette, Editor