Waterproof breathable fabrics consist of an outer layer called the “face fabric”, usually made of nylon or polyester, and a laminated membrane or coating, usually made of ePTFE (expanded Polytetrafluoroethylene, also known as Teflon) or PU (Polyurethane).

Dry Bags provide at Watertight enclosure by the way they are secured. ... Instead of a Ziploc type of closing mechanism, the bag is secured by rolling down or dog-ear the top at least 3 times, them clipping the buckles together. See my post about the proper way to close a dry bag here.

The difference between water-resistant and waterproof arises from the fabric. A water-resistant material is so tightly woven that water struggles to get through. ... A waterproof material, on the other hand, provides a complete barrier to water.

After your pack is dry, you can spray it down with the waterproofing spray, following the manufacturer's recommendations. Usually, you need to apply one or two coats of spray and then hang the bag to dry. Once the pack is dry, you can go through it and use the seam sealer to tape up all of the seams......

A Polyurethane Coated 4 Way Stretch Spandex Tricot Polyester that is 190+40 GSM - 85% Polyester, 15% Spandex. This wind and waterproof stretch fabric resembles a super thin neoprene with a very soft black polyurethane coating and an amazing amount of flex. This polyester 4 way stretch spandex is non......

As water-repellent materials usually do not contain any kind of membrane of compact coating, the so called breathability of these materials is in most cases better than the one in waterproof materials.