MYLAR® RL4 is a FDA compliant biaxially oriented polyester with an EVA heat seal layer. It is used as a heat sealable lidding film in packaging frozen and refrigerated food. RL4 requires lower seal initiation temperatures than lidding films with an APET heat seal layer. This film's heat seal layer and strength is intermediate between RL31 and FL32.

MYLAR® is a registered trademark of DuPont Teijin Films for its polyester film. Only DuPont Teijin Films make MYAR®