PURPOSE: To facilitate color chip attaching work by superposing a transparent or translucent film, on which ruled lines forming a grid are printed, on the top of a design, and temporarily fixing it.

CONSTITUTION: The design 1 is observed from the position above the film 2 which is superposed on the top of the design 1, and is temporarily fixed; various color chips 6, 6,... are peeled from a release paper 7, and are successively attached to the top of the film 2, for each of squares 4, 4,... superposed on the design 1, so as to correspond with the colors of the design 1. In this way, a mosaic picture for the design 1 can be generated by attaching the color chips 6, 6,... to the entire surface of the film 2.