Dry bags are typically made from vinyl, vinyl-polyester laminates or PVC-coated ripstop nylon. Vinyl is often found in smaller bags, like those specific to phones and cameras, as the material allows buyers to actually see or use the item in the bag. Nylon bags, with a waterproof coating, are often the most flexible alternatives. The denier rating (ex. 500D) indicates how dense the nylon fibers are; the higher the number the stronger the bag.