Method of preventing color accurate reproductions using color photocopiers and the like

摘要

A method of preventing color accurate reproduction of a colored pattern with color photocopiers or color photography using photosensitive materials having spectral sensitivity in the wavelength ranges consisting of the human visible range and the adjacent wavelength ranges thereto, comprising, forming at least portion of the colored pattern with a color material having a spectral reflection factor curve with high spectral reflection in at least one of the areas of wavelength below 450 nm and above 650 nm so that a reproduction of the colored pattern is in a color not perceivable by a direct human viewer of the colored pattern. The color material also has at least one high spectral reflection peak or area within the human visible wavelength range so that the perceived color of the colored pattern is different from a reproduced color using color photocopiers or photography.