The canvas is used in many ways to protect people and things from wind, rain, and sun. They are used during construction or after disasters to protect buildings under construction or damage, to prevent contamination during painting and similar operations, and to store and collect waste. PVC tarpaulin is a three-ply cloth that contains a scrim clip inserted between two sheets of polyvinyl (PVC) film. http://www.hdl-corp.com/tarpaulin/pvc-tarpaulin/