An image of a sample print printed to obtain parameters is picked up by using “a parameter obtaining device” that meets the standards of an instrument for the invention of “the electronic scrap system.” Then, the picked-up image is captured by a DTP system, and color data of a needed position are imported to a parameter DB. Thereby, parameters for simulation to be used in an invisible code printing support system can be easily inputted. Use of this method eliminates the necessity of figuring out parameters through experiments and the like, and of inputting these parameters as numerical values. In addition, since this method uses a physical medium and inks to be actually used, as they are, their optical characteristics, an influence of a blue component of invisible light emitted from an ultraviolet LED, and the like can be inputted all together as a picked-up image. Accordingly, it becomes possible to input parameters capable of accurately reproducing actual printed conditions, and thereby to produce printed materials providing high reading accuracy.