Patagonia developed the 4-layer fabric construction for our waders to increase breathability and abrasion resistance, move moisture away from the body, and decrease the weight. Our exterior fabrics are densely woven 100% polyester microfibers for durability and puncture resistance. On one side we apply our H2No® waterproof coating for waterproof/breathable performance. On the other side we apply a Hydrophilic laminate that pulls moisture away from the body so it can be passed out through the exterior shell. To protect the hydrophilic laminate we use a soft polyester tricot lining that increases abrasion resistance yet maintains a soft, supple drape. Finally, we apply a DWR (durable water repellent) treatment as the first line of defense in keeping these waders waterproof.