Parafilm M is flexible, thermoplastic, waterproof self-sealing film that holds moisture loss to the minimum and offers secure sealing to the content of tubes, beakers, flasks, petri-dish and vials.
It has excellent resistance to air, other gases, alcohol, common acids and moderately concentrated alkalis.
At 21C (70 F), it stretches 200% and returns partially to its original size at 82 C to 93C (180 F to 200 F) and softens enough to make an adhesive bond between papers, cloths and leathers.