Sheet Having Convex Pattern on Surface and Method for Forming the Convex Pattern

摘要

A method for forming a convex pattern on a surface of a sheet includes the steps of covering a photosensitive resin film 21 with a masking film 4 having a convex forming area 40 corresponding to a convex pattern to be obtained, exposing the photosensitive resin film 21 to light from an outside of the masking film 4, and removing an unexposed portion of the photosensitive resin film 21 subjected to the exposing step, thereby forming a sheet 2 with an exposed portion 22 left, and the convex forming area 40 of the masking film 4 has a semi-translucent portion 43 and a translucent portion 41 formed in sequence at an outside of a light-shielding portion 42 in order to express a shade in gradation, and a light transmittance increases stepwise from the light-shielding portion 42 toward the translucent portion 41.