A non-reactive, non-soluble material used for coating the surface of the material to be etched. The etching ground is usually heated then a thin layer is rolled or brushed onto the metal plate. A hard surface etching ground is made from mixing beeswax, asphalt and rosin. A soft surface etching ground may consist of the hard surface mixture diluted with axle grease, tallow, Vaseline® or mineral oil. An etching ground called sugar lift is composed of corn syrup, India ink, soap and gum arabic while white etching ground contains titanium dioxide, soap, linseed oil and water (McCann, 1979).
M.McCann, Artist Beware, Watson-Guptill Publications, New York, 1979.