From Greek xeros (dry). A dry copying technique for the electrophotographic production of paper copies based on black and white templates. Using selenium as a semiconductor, a light sensitive layer is produced. When exposed to light, the layer is charged electrostatically. Colour powder (toner) is then distributed on the layer and attracted to the electrostatically charged areas of the paper. As a result, the electrostatic image becomes a visual image. In order to affix the powder to the paper, the paper is exposed to heat or pressure.
See also photocopy.