Description: (Large bag in photo) This sandwich bag is made of lightweight cotton on the outside, and is double layered with ripstop nylon (food safe) on the inside, and has a velcro closure. Note: Many other bags are made with PEVA or PUL. Neither of which are considered food safe. Since the lining is made with water proof material, both wet and dry snacks work for each bag. However, the bag itself is not water proof (the seams will eventually leak).