What Is Soft-Ground Etching?

Ground Composition

• Soft etching grounds are made from a combination of rosin, beeswax, tallow and asphaltum. This combination of materials won't dry to a hard surface like hard ground wax. It is also less acid resistant than hard ground. Lines scribed into this material by an artist deepen and widen the longer they're exposed to the acid.

Ground Application

• To apply soft ground to an etching place, the artist heats the copper plate to be etched to around 135 degrees Fahrenheit using a hot plate or propane torch. A dedicated brayer, or roller, is then used to spread the soft ground onto the hot metal, which melts and smooths it. The artist rolls the brayer over the ground surface with gradually lighter pressure to smooth it, to remove roller marks and to reduce the risk of pinholes. The prepared plate then is allowed to cool.

Drawing

• Placing paper over the surface of a soft ground plate, then drawing on the paper, produces a line similar to that made by a pencil or crayon. The finer the paper texture is, the finer the finished lines will be. Stronger pressure creates a deeper line. Artists can also use thin, flat materials, such as leaves, fabric or gauze to imprint a texture onto the ground surface. The plate is placed into the press with the textured material on top, then covered in a piece of waxed paper and a rubber printing blanket. The artist presses the plate as though making a print, using light pressure, and imprints the texture into the soft wax.

Etching

• Soft ground plates are etched just like hard ground plates, using ferric chloride, a corrosive salt that works much like acid. Older soft ground printing methods used nitric acid or Dutch Mordant, a material made of water, potassium chlorate and hydrochloric acid. These older materials tend to produce harmful gaseous emissions and can burn the skin. Ferric chloride stains skin but does not burn or off-gas. Artists usually etch a test plate before placing the soft ground plate into the bath to determine the appropriate etching time.