| 摘要 |
PURPOSE:To enable selective coloring of only a background part of a predetermined image region, by selecting a pigment ink having a critical surface tension lower than those of a recording sheet and an image forming material, and placing the pigment ink on the recording sheet in the state of maintaining the fluidity thereof. CONSTITUTION:At the time of selectively coloring a background part of a predetermined image region on a recording sheet provided with an arbitrary image formed of an appropriate image forming material, a pigment ink layer having a critical surface tension gammac3 (dyn/cm) satisfying the relationship gammac3<gammac2<gammac1, where gammac1 (dyn/cm) is the critical surface tension of the recording sheet and gammac2 (dyn/cm) is the critical surface tension of the image forming material, is placed on the recording sheet in the state of maintaining the fluidity thereof. The pigment ink on the image forming material, which has a small difference in critical surface tension, is attracted to the side of the recording sheet, which has a large difference in critical surface tension. Therefore, the pigment ink layer is not left on the image forming material, and the background part of the predetermined image region can be selectively colored. |
