Mylar® RL32 (formerly known as XM999) is a biaxially oriented polyester (OPET) film with an ethylene vinyl acetate (EVA) heat seal layer. It is used as a heat sealable lidding film in packaging frozen and refrigerated foods. Mylar® RL32 is designed to seal to a broad range of container substrates including amorphous polyester (APET, also PETG), semicrystalline polyester (CPET), polyester coated paperboard, polyvinylchloride (PVC), polyethylene (HDPE), polypropylene (PP), and polystyrene (HIPS). Mylar® RL32 has the same type heat seal layer as Mylar® RL31, but the thickness of the heat seal layer and the heat seal strengths of Mylar® RL32 are intermediate between Mylar® RL31 and Mylar® RL33. Mylar® RL32 and Mylar® RL4 produce similar heat seal strengths to most substrates, but Mylar® RL32 has a greater tendency to produce tearing seals while Mylar® RL4 tends to produce more peelable seals. Like Mylar® RL31, Mylar® RL32 has a lower seal initiation temperature than lidding films with an amorphous polyester heat seal layer (e.g., Mylar® OL, OL2). This allows good seals to be made at higher line speeds (or using lower sealing temperatures).