1. A metallic alloy of a deep black color. 2. The art, process, or method of decorating metal with incised designs filled with the black alloy. 3. A piece of metal, or any other object, so decorated. 4. An impression on paper taken from an ancient incised decoration or metal plate. NIEPCE'S PROCESS Niep"ce's proc"ess. (Photog.) A process, now no longer used, invented ...