To provide a woven pattern print density adjustment support program for maximizing contrast after copying a pattern.

The program has a density adjustment function. THe density adjustment function includes a first step for displacing dot density in a latent image for density adjustment and dot density in a background section by each fixed width, generating a patch image in which a latent image and the background are drawn by the combination of their values, and arranging the patch image in a matrix shape at a printing region for printing a test chart; a second step for allowing a user to input a plurality of patch image groups in which the contract of the latent image section and the background section is within a tolerance from the test chart; a third step for allowing the user to input the plurality of patch image groups in which the contrast of the latent image section and the background section is within a tolerance from a test patch in a test charge duplication obtained by copying the test charge duplication; and a fourth step for determining one optimum patch image from the plurality of patch image groups in two series input in the second/third steps.