The Color Stable Series incorporates a unique process for producing nano carbon polyester. This revolutionary process allows for maximum heat rejection without a metal film layer, which can interfere with radio and/or satellite signals. It also gives the film a stylish look with outstanding color stability, so it never turns purple. Improving comfort, protecting vehicle interiors and blocking UV rays are hallmarks of 3M™ Automotive Window Films. 3M was issued the first sun control window film patent in 1966, and our innovative window film products have helped provide protection from the sun’s harmful rays for 50 years.