a reflective film suitable for reflecting light and radio frequency energy includes a thin annealed metal foil affixed to a polymeric carrier layer or substrate wherein the polymeric carrier is thicker than the metal foil so that the foil tends to assume the physical properties , and particularly the elongation of the carrier without rupture or surface cracking of the foil upon stretching . in this manner , the polymer - metal foil laminate can be substantially deformed and stretched to fit complex shapes while maintaining a continuous , 100 % reflective foil layer . the elasticity and yield strength of the substrate are selected to permit the combined foil and substrate to be stretched to fit complex shapes .