Method of producing a patterned birefringent product

A method of producing a patterned birefringent product, comprising at least steps (I) to (III) in this order:

• (I) providing a birefringent pattern builder having an optically anisotropic layer containing a polymer having an unreacted reactive group, the optically anisotropic layer being obtained by coating with a solution containing a liquid crystalline compound having two or more types of reactive groups each of which having different polymerization condition, drying the thus-coated solution to thereby form a liquid crystal phase, and then applying heat or irradiating ionized radiation to the liquid crystal phase to thereby cause polymerization and fixation;
• (II) subjecting two or more regions of the birefringent pattern builder to patterned light exposure under exposure conditions that differ from each other in at least one of exposure intensity, exposure quantity, exposure time period, and exposure peak wavelength;
• and
• (III) heating a laminated structure obtained after the step (II) at 50° C. or higher and 400° C. or lower.