How to choose a Poly Tarp (Polyethylene Tarpaulin) Poly Tarps are one of the most popular tarps available to consumers due to the wide range of colors, sizes, weights/strength and price. You need to select the right tarp for your application whether you are covering a canopy, carport, construction job, tent frame, outdoor event, yard project or wedding. [Construction] Poly Tarps are typically made of multiple layers with a woven mesh fabric sandwiched between two or more polyethylene sheets. [Reference Parameter] Tarp Thickness– This is the actual thickness of the tarp measured in mils (1/1000 of an inch). The larger the number, the thicker the tarp. Typical light weight tarps found in most retail or hardware stores are about 4~6 mils. If you are planning a heavy duty use, such as covering a carport, consider a heavy duty tarp at 10 to 16 mils. Reinforcement– Tarps have additional reinforcement around the perimeter of the tarp to help prevent ripping and tearing. * Perimeter rope– This is a rope which has been sewn inside the hem at the edge of the tarp to add reinforcement strength to the tarp. * Hem– The hem is formed by folding the edge of the tarp back onto the tarp and then stitching the entire hemmed area. [Warning] Flammable. This Product will ignite and burn if brought into contact with an open flame. Suffocation hazard. Do not allow children to play with tarp.