A means of adding extra-trinary colors to process color printing. A touch plate consists of a plate of a special color beyond the traditional cyan, magenta, or yellow. Touch plates are used to reproduce a color which is out of the gamut of CMY mixing, used especially to reproduce a unique color in the original artwork. See Extra-Trinary Color. See also Color Substitution and Bump Plate.
In multi-color screen printing, a touch plate is a fifth (or otherwise additional) screen for the printing of so-called non-reproducible colors such as fluorescents or whites.