A two-color halftone produced by overprinting two halftone screens made from the same photograph (usually a black-and-white photograph), as a means of generating a monochromatic image with a full range of tonal gradations. In the creation of a duotone, two halftone plates are made, one for black, which picks up the highlight and shadow regions, and one for middle tones, either other shades of black, or another color. When two non-black colors are used in the production of a duotone, it is often called a duochrome. Duotones are often made to increase detail in the black regions of an image, or as a special effect. Often, only one halftone is printed, the second plate being a solid color, thus creating what is known as a fake duotone. See also Tritone and Quadratone.