Shrink wrap (AKA heat activated shrink film) is a type of plastic wrap that shrinks when heated. It is used to insulate windows, provide a protective wrap for winterized boats (boat shrink wrap), seal food and pharmacy containers and packaging, and put the finishing, containing seal on all kinds of merchandise. Typically made of a PVC film or polyolefin, shrink wrap is sold as individual shrink bags, shrink tubing, or shrink rolls. Items may vary by thickness, width, length, compatibility, package quantity, roll length and other considerations. For more on plastic wraps, see our stretch wrap, protective packaging, and shrink wrapping machines.