SilverBack® 20 Mil Vapor Barrier The front of the SilverBack® is white and the back is Silver. As always, the SilverBack® brand of vapor barriers are true thickness, so this 20 Mil vapor barrier measures 20 Mil at the plastic not the string reinforcement like the others. This means you get 22%-30% more plastic than with other products on the market calling their product a 20 Mil The 20...