Abstract: A method of manufacturing a wrinkle coupon includes providing a thermoplastic laminate having a laminate outer surface and opposing laminate side edges, and comprised of multiple plies. Each ply is comprised of reinforcing fibers pre-impregnated with thermoplastic resin. The method additionally includes placing a wrinkle-forming element across the laminate outer surface such that the wrinkle-forming element extends between the laminate side edges. In addition, the method includes applying heat to the thermoplastic laminate, and applying compaction pressure on the wrinkle-forming element against the laminate outer surface in a manner urging the wrinkle-forming element into the thermoplastic laminate, and causing the wrinkle-forming element to form a wrinkle as an out-of-plane deformation in one or more of the plies. The method also includes allowing the thermoplastic laminate to cool, and cutting a wrinkle coupon out of a region of the thermoplastic laminate containing the wrinkle.