Shrink wrap, also shrink film, is a material made up of polymer plastic film. When heat is applied, it shrinks tightly over whatever it is covering. Heat can be applied with a hand held heat gun (electric or gas) or the product and film can pass through a heat tunnel on a conveyor. ==Composition== The most commonly used shrink wrap is polyolefin.{... Found on http://en.wikipedia.org/wiki/Shrink_wrap