Rack Mark. Evidence on a medallic item at three or more points in which coloring, finish or lacquer is missing. The tiny points are where the medallic item was supported while it was worked on, as during a finishing or lacquering operation. Rack marks usually appear at three equidistant points along the edge where the supporting prongs, wires or stilts make a point of contact and thus prevent any finishing at those points. See stilts.
excerpted with permission from
For Artists, Makers, Collectors and Curators
COMPILED AND WRITTEN BY D. WAYNE JOHNSON
Roger W. Burdette, Editor