6 oz. per square yard. 11-12 mil thickness Light Block Out Tarp Grommets Spaced 18 inches apart - Reinforced Corners UV stabilizers on both sides Finished 6 inches or up to 2 percent smaller Made of woven polyethylene, tarps are waterproof and tear resistant, UV lamination, heat-sealed seams, grommets, and reinforced edging with strong poly rope inside hem on four sides.