Asphaltum - enacademic.com
2015-4-30 · Look at other dictionaries: asphaltum — [as fal′təm] n. ASPHALT … English World dictionary. asphaltum — In etching, a liquid that is used on plate as a soft ground, and on the backs of plates to protect them from the mordant. In lithography, asphaltum is used to chemically process the drawing.