ATI employs this technique, especially in, but not limited to, twin-sheet molding, where exceptional stiffness is required. In this case, we mount metal reinforcement structures in the mold prior to forming. Next, we form the part so the material “wraps around” the reinforcement in selected areas, entrapping it inside the part. Thus, significant additional structure is provided. In addition, we can generally generate a lower cost than with the alternatives of foam-filling or thicker starting plastics.