Shrink bands are placed around the bottle neck and closure in the final step. Heat is then applied, and the shrink band melts to form a tight tamper-evident seal. This shrink band has been perforated, a dashed series of incisions have been made in the shrink band to make it easier for the end user to remove. Polyvinyl choride (PVC) is marked with the resin identification code of 3. Over half of PVC is cholorine, requiring less petroleum that other plastics. PVC has medium clarity, good chemical resistance, good impact resistance, medium rigidity, and medium scratch resistance.