Made from premium grade virgin polyethylene resin. Most plastic manufactures can't say that and be truthful! Our original 12 Mil SilverBack DrySpace brand crawl space vapor barrier is now known as our Commercial Grade Mil SilverBack DrySpace! The top of the DrySpaceis white and the back is Silver. Our Commercial Grade 12 Mil vapor barrier is true thickness, so our 12 Mil measures 12 Mil at the barrier not the string reinforcement. This is the product our contractors use in their professional installations. Due to the increased availability of low quality "white" plastic from China being sold as a crawl space vapor barrier we have decided to change how our American Made DrySpace vapor barriers looks. You still get the absolute best quality and performance as well as the technical support you need to install our products and answer your questions. The 12 Mil SilverBack DrySpaceis the best all around choice for most crawl spaces. It will handle light to medium storage requirements as well as traffic for regular home maintenance. If the DrySpaceis going to be installed over sharp stone consider installing our Felt 550 first to protect your DrySpace investment. This is the most popular DrySpacevapor barrier for crawl spaces due to its lower cost and high performance. This product is string reinforce and naturally resists Mold and Mildew.