A type of imagesetter, a device used for high-resolution laser output of digitally-created pages or ["color separation"s]. On a drum imagesetter, the digital file is converted to film format, and the film to be exposed is, in an external drum imagesetter, mounted on the surface of a drum or, in an internal drum imagesetter, mounted inside the drum. Digital information is used to guide the laser in the line-by-line exposure of the film. An alternate type of imagesetter is a flatbed imagesetter, in which the film is exposed by moving it with rollers past the imaging source. Of the two, drum imagesetters are widely believed to generate the better quality output. (See also Imagesetter.)