This 20 ft. x 40 ft. Woven Poly Tarp is Waterproof, Mildewproof, Tear Resistant and Acid Resistant. 3.3 oz. per square yard, 6 mil thick, 10×10 weave count, grommets approximately every 24″and reinforced corner grommet. Finished size approximately 2% or 6″ shorter. Tarp is lightweight yet durable, manufactured from high-density polyethylene and woven into fabric and then laminated with a Camouflage Print one side and green the other side then finished by hemming the edges with poly twine inserted in hem. All seams and hems are heat sealed. UV Treated.3