thermoforming of film having deep draws is usually done using plug forming in order to achieve part shape and thickness uniformity. however, the design of the plug shape and material selection are important during the production stage. in addition, the dimensional variation of the printed pattern and thickness of the formed film also have significant effects on the injection molding process. if the thickness distribution of the formed film is non-uniform, cracking, deformation, warpage, and wrinking at the injection molding stage can easily occur