Gimmick expression medium producing method and data processing method for gimmick expression medium

A gimmick expression medium producing method for forming a printing layer which produces a gimmick effect for a printing medium using the printing medium having a light-transmission layer,

• the method comprising:
• a light-blocking layer forming step of partially covering the light-transmission layer of the printing medium to form a light-blocking layer for blocking light on the printing medium;
• a reflection picture print step of forming a reflection picture on the light-blocking layer;
• and
• a gimmick print step of forming a gimmick print layer to vary color of light which passes though the light-transmission layer to produce the gimmick effect, wherein
• in the light-blocking layer forming step, the light-blocking layer is placed on the printing medium to cover the light-transmission layer of the printing medium using a stripe-shaped or dot-shaped lattice pattern,
• the reflection picture and the gimmick print layer are placed in adjacent to each other by the stripe-shaped or dot-shaped lattice pattern without overlapping, and the reflection picture print step of forming the reflection picture and the gimmick print step are carried out by one step (one-pass) using common image data using a same printer.