In etching the term grounding is used for the application of a layer of acid resistant substance to the plate surface. This acid resist is then worked with pointed tools so as to remove it in areas that will be later etched by the mordant. Grounding can be done cold with a liquid ground applied with a brush.
Cold grounding is used for quick work and retouching.
However, when the liquid ground is applied with a brush it is not a bad idea to heat it slightly so that it will spread with greater ease. A burnt ground can be recognized because it begins to smoke and because it becomes covered with spots and bubbles. The heating of the ground must be uniform and gentle. A solid ground can also be applied with a dabber , in which case the ground is kept in a little silk bag with which one strikes the heated plate all over the surface. This striking deposits a regular layer of ground which is then spread with a leather or silk dabber.