A ground is waxy material applied to the surface of a metal

etching Etching is traditionally the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio (incised) in the metal. In modern manufacturing, other chemicals may be used on other type ...

plate. A metal etching plate is a piece of

sheet metal Sheet metal is metal formed into thin, flat pieces, usually by an industrial process. Thicknesses can vary significantly; extremely thin sheets are considered foil (metal), foil or Metal leaf, leaf, and pieces thicker than 6 mm (0.25 ...

, usually

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic tabl ...

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

, or

aluminium Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

. The ground resists the acid or mordant which is used for etching, protecting areas of the metal plate. Grounds are made from a variety of materials including tar, asphaltum,

paint Paint is a material or mixture that, when applied to a solid material and allowed to dry, adds a film-like layer. As art, this is used to create an image or images known as a painting. Paint can be made in many colors and types. Most paints are ...

(including spray paint),

oil pastel An oil pastel is a Art medium, painting medium that consists of powdered pigment mixed with a binder (material), binder mixture of non-drying oil and wax. Oil pastel is a type of pastel. They differ from other pastels which are made with a gum ...

s, and other materials manufactured specifically for etching. Most commonly, a ground is applied evenly over the surface of the metal sheet (also known as the etching plate), and then removed using scratching and other mark making techniques to reveal bare metal underneath. In the traditional technique this is done with a metal needle. However, different grounds enable the artist to create different types of marks. Some types of grounds, such as an

aquatint Aquatint is an intaglio printmaking technique, a variant of etching that produces areas of tone rather than lines. For this reason it has mostly been used in conjunction with etching, to give both lines and shaded tone. It has also been used ...

ground, are more complex and may not include a removal process because they are applied in a selective manner. The areas of the metal plate that are exposed will be etched by acid or mordant, while the ground resists the acid. The etched areas will have indentations, grooves, or cavities, while the areas that had a ground on them will typically remain the same as before the etching process.

References

{{reflist Printmaking Etching