Opaque black,translucent white or pale gray non-lead fotoform; photosensitive glass has photographic image transferred to it and submitted to light, then acid-etched. Two flat circular disks: (A) opaque white, both sides covered with intaglio design of two grids crossing at right angles to form a square comprised of small squares, on one side the lines are etched to a greater depth creating the appearance of a tan background; (B) opaque black, both sides decorated with intaglio line drawing of a section of the Corning Incorporated headquarters located on the banks of the Chemung River, image sits within a circular, very narrow linear border; chipped side section reveals that disk is a "sandwich" of two layers of glass, one is solid black, the other fades from black at the exterior to colorless; impressed in block letters at center right edge (both sides) of white example: "CORNING".