Patent ID: 7691554

Claim:
An image forming method of forming a color image on a predetermined base material expressing a color to be expressed for each pixel by a combination of luminances of color corresponding to each of a plurality of diffraction gratings and black ink, by transferring each of the diffraction gratings is transferred from a transfer sheet in which the plurality of diffraction gratings are laminated on the base material, the plurality of diffraction gratings being different from each other in a color of diffracted light observed in a particular direction, and forming a black ink layer being constituted black ink, wherein the image forming method comprises: a black ink forming process of transferring the black ink layer onto the base material from a black ink transfer sheet having the black ink layer constituted by the black ink such that the black ink layer covers an area of the base material corresponding to the color image; and a diffraction grating forming process of forming the diffraction grating corresponding to the each color on the black ink layer formed on the base material such that luminance of the each color becomes luminance appropriate for the color to be expressed.