Desktop Publishing involves the presentation of textual material in graphic form on paper or some other medium. It consists of a character matrix in the form of film negative, which has the images of all the characters, a light-sensitive paper and a light source. The characters in the matrix are exposed to the photographic paper by the light source through a lens one by one as they are typed in the keyboard, in a similar way to that of typewriters. The exposed photographic paper is developed and used as a master for reproduction of plates, which is required for the printing process.