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. Sheet metal is one of the fundamental forms used in metalworking, and it can be cut and bent into a variety of shapes. Thicknesses can vary significantly; ex ...

, usually

copper Copper is a chemical element with the symbol Cu (from la, cuprum) 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 ...

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc 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 t ...

, steel, or

aluminium Aluminium (aluminum in AmE, American and CanE, Canadian English) is a chemical element with the Symbol (chemistry), symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately o ...

. 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 Tar is a dark brown or black viscosity, viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic matter, organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. ...

, asphaltum,

paint Paint is any pigmented liquid, liquefiable, or solid mastic composition that, after application to a substrate in a thin layer, converts to a solid film. It is most commonly used to protect, color, or provide texture. Paint can be made in many ...

(including spray paint),

oil pastels An oil pastel is a painting and drawing medium formed into a stick which consists of pigment mixed with a binder mixture of non-drying oil and wax. They differ from other pastel sticks which are made with a gum or methyl cellulose binder, and ...

, and other materials manufactured specifically for

. Most commonly, a ground is 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