2-layer H2No^® shell fabrics are completely waterproof, windproof and breathable. They utilize an internal mesh or a wicking, hanging fabric liner to protect the H2No waterproof barrier making them very comfortable and warm, even against the skin. 2-layer shell fabrics are versatile alternatives when you don't need the lightest or most durable shell available.

Testing and Development

“We reject 93% of the fabrics we evaluate because they don’t perform to our standards. The remaining 7% we subject to further rigorous testing and analysis during product development – and from each production lot – to make sure those standards are continuously met.”
–Randy Harward, Director of Quality

No lab method simulates Mother Nature perfectly, but lab testing can help develop and accurately compare fabrics for specific performance characteristics. At Patagonia, we use the most highly controlled and technology-neutral methods available that most closely simulate actual-use conditions. We test a fabric’s waterproofness by simulating light rain, long-term rain and by forcing water through the face of the fabric. We make sure that a fabric is breathable by measuring its Moisture Vapor Transmission Rate (MVTR).

All products bearing the H2No mark have been vigorously tested for durability in a process called 24 Killer Wash, used to simulate years of use and abuse in a short period of time. This process consists of exposing the fabric to severe thrashing in a modified washing machine for a continuous 24 hours. After the killer wash, we test products for water permeability, adhering to a standard almost twice that of the U.S. Military.

No approach taken in the lab stands on its own; everything must be confirmed with adequate field testing. For our Field Test Program, a group of trained experts in a variety of climatic bases take prototypes out in to the field and use them in the activities and conditions for which the products are intended. Only a handful of prototypes we test ever make it into the product line. The idea: we endure some misery in the field so our customers don’t have to.

Environmental Impact
To determine the environmental impact, we look at the lifecycle of the product, including end-of-life disposal, and the toxin levels in the manufacturing process. The most environmentally harmful component of a waterproof shell is the waterproof/breathable barrier. It is usually made from three different chemical compounds: polyester (PES, PET), polyurethane (PU) and polytetrafluoroethene (PTFE). As of fall 2008, Patagonia does not use polytetrafluoroethene (PTFE) – the most harmful of the three chemicals – in our waterproof/breathable membrane construction.