PURPOSE: To enable to produce a three-dimensional poster provided with a desired pattern, by a method wherein a pattern is printed on the surface of a sheet suitable for printing and vacuum forming in accordance with a transferred figure, followed by vacuum forming.

CONSTITUTION: Small ruled squares are drawn on the surface of the sheet 2 along orthogonal coordinates, and x- and y-coordinate values 2x, 2y are written- in. The sheet 2 is subjected to vacuum forming by using a mold 1, thereby providing a projected part 1' having substantially the same shape as that of the mold 1. Borders are drawn or painted along the boundaries of projections and recesses, the coordinate values are read in terms of distorted x-y coordinates, and the read values are plotted on a non-distorted x-y coordinate plane. After coloring, a multicolor printing plate is produced by photomechanical process, and printing is conducted on a printable and vacuum-formable sheet by using the printing plate. The sheet thus printed is subjected to vacuum forming by using the mold 1. After each part of the sheet is enlarged, contracted or deformed by vacuum forming, the desired pattern is obtained.