| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a simplified technique for distinguishing by the naked eye between the original print and a fake thereof without the aid of sophisticated printing techniques or high-precision instruments for discrimination when not a few of the measures for suppressing or preventing the forgery of convertible documents demand special printing technologies or expensive measuring devices, with a great mass of securities, banknotes, gift tokens, and cards in circulation and with their faking and forging occurring frequently. SOLUTION: A printed material is prepared by using an ink composed of a plurality of coloring matters seemingly the same but quite different in reflection and absorption characteristics across the range from long-wavelength red to infrared. In such a printed material, patterns and figures scarcely identifiable from each other are formed into a color copy, when some deviation is generated in hue and concentration enabling the naked eye to evidently detect the difference between the two. This allows true/fake identification to be accomplished easily in a short time period.</p> |
