| 摘要 |
PROBLEM TO BE SOLVED: To form a sealed letter capable of precluding decipher from being done through the transparency of duplicated information from the top face of the sealed letter without thickening the paper thickness of the sealed letter cover paper or without printing ground pattern on the rear face of the sealed letter cover paper. SOLUTION: The sealed letter is to implement duplication in a duplication entry part of the paper surface side of a sealed letter located at the lower place of the sealed letter cover paper 2 by pressure applied from the surface side of the sealed letter cover paper 2, in which a developer layer 10 is provided on the duplication entry part of the sealed paper, and a developer microcapsule agent layer is applied to the rear surface side of the sealed letter cover paper 2 corresponding to the duplication entry part of the sealed letter paper, thereby forming such a developer microcapsule agent layer 11 corresponding to a predetermined duplication entry part of the sealed letter paper consisting of a color developer mirocapsule layer 12 containing a coloring agent. |
