Panda Film 10ft. x 100ft. 5.5 Mil Black and White FilmImprove the efficiency of lighting with the 5. 5ml thick black and white filming. Both sides of the filming have a purpose, like the white side, which allows light to reflect by 90%, whereas the black part does not let light penetrate. The film is heavy duty and waterproof, due to which it does not allow the growth of algae and mold on the walls. High Reflectivity: The white portion is 90% reflective, while the black part does not allow light