The reflectivity of household aluminum foil is satisfactory, but depending on the intended application, alternative materials may be more suitable. Thicker aluminum sheets or flashing can be polished to direct light in a specific direction rather than reflecting it diffusely. Mylar (BoPET with vapor deposited aluminum) is an excellent reflector and can provide superior reflectivity compared to aluminum foil; however, it may also be more costly depending on its thickness.
