Our all new blue poly tarps are better than ever 7 Mil thickness, Mildew resistant. These blue poly tarps are strong, tear resistant and have a high density polyethylene. Most blue poly tarps have become a standard amongst the roofing industry and government agencies. The blue poly tarps are always the #1 choice for hurricanes. Most blue poly tarps that you see at your regular hardware store are not heavy duty poly and tear easily or collect mildew. Our blue poly tarp is the most economical and best quality tarp out on the market, if you are looking for the best of the rest pick up one of our blue poly tarps.