PURPOSE: To improve gradation with a simple structure by forming a donor layer made of a copolymer containing predetermined ratio of an acrylonitrile, an n-butyl acrylate, 2-hydroxyethylene methacrylate and a coloring material on a base film.

CONSTITUTION: The donor film formed on a base film made of a polyethylene phthalate or the like comprises a polymer material containing coloring materials of cyan, magenta and the like and a terpolymer. The polymer material is formed of a copolymer obtained by polymerizing a reaction composition containing 24 to 45 wt.% of an acrylonitrile, 35 to 55 wt.% of n-butyl acrylate and 10 to 30 wt.% of 2-hydroxyethylene methacrylate, wherein the % are with respect to overall monomer.