With two layers the outer layer can stick. The inner layer stays stuck to you. The two layers slide, hopefully reducing the skin abrasions. A tough outer surface is critical else the fabric just disintegrates. The inner layer just needs to be thick enough to resist abrasion from the slippery out layer. There are some fancy camera bags I checked out and they have this slippery lycra-like fabric that's really thick. It reminds me of the stuff on the dual layer shorts.