A simple linear polarizer can be made by tilting a stack of glass plates at Brewster's angle to the beam. Some of the s -polarized light is reflected from each surface of each plate. For a stack of plates, each reflection depletes the incident beam of s -polarized light, leaving a greater fraction of p -polarized light in the transmitted beam at each stage. For visible light in air and typical glass, Brewster's angle is about 57°, and about 16% of the s -polarized light present in the beam is reflected for each air-to-glass or glass-to-air transition. It takes many plates to achieve even mediocre polarization of the transmitted beam with this approach. For a stack of 10 plates (20 reflections), about 3% (= (1 − 0.16)) of the s -polarized light is transmitted. The reflected beam, while fully polarized, is spread out and may not be very useful.