Abstract: A method of preparing printing plates for printing leaflets, catalogs or the like using a computer. The design for a leaflet, a catalog or the like is classified into line drawings, photographs and characters and they are introduced into a computer through predetermined input units, respectively. Then, they are laid out while being displayed on a display and how they have been laid out is confirmed by the hard copy. The press plates for printing are prepared on the basis of data output from the computer. Additionally, a method of laying out line drawings, photographs and characters on a display with high efficiency. The line drawings are laid out by designating the size and the angle of the line drawing to be laid out on a display in an analog fashion. The photographs are laid out by displaying only the contour line of the photograph on the display.