| 摘要 |
PROBLEM TO BE SOLVED: To provide an ink jet information recording medium capable of simply and surely conducting a decision of a truth or a falsehood and executed by a forgery preventing remedy so as not to conduct a forgery by a printing technique or an electronic copier. SOLUTION: A base having a heat discoloration layer for heat discoloring by a temperature is cut. Cut small pieces are watermarked in a paper layer. The discoloration layer or both surfaces of the discoloration layer and the base are exposed so that its color is changed by a temperature change. Thus, a truth or a falsehood can be simply and easily decided, and the forgery is very difficult. |
