| 摘要 |
A printed material of an embodiment, as a printed material where a main image is printed on a base material, has a first secondary image having colors which are visually identical to those of the main image to people, printed with ink which can absorb light in infrared wavelength region with first absorption rate, and inserted into the main image, and a second secondary image having colors which are visually identical to those of the main image to people, printed with ink which can absorb light in the infrared wavelength region with second absorption rate, and inserted into the main image. |
