Waterproof fabric

They are usually natural or synthetic fabrics that are laminated or coated with a waterproofing material such as wax, rubber, polyvinyl chloride (PVC), polyurethane (PU), silicone elastomer, or fluoropolymers.

Their ability to block out rain and snow while allowing vapour from sweat to evaporate leads to their use in rainwear, waterproof outdoor sports clothing, tents, and other applications.

[clarification needed] However, some garments made from fabrics that exceed 20 000 mm have leaked through zips, hoods, and seams.

These are directional fabrics such as Nikwax Analogy and FurTech, which are also breathable in the conventional sense (although these examples are actually a combination of two different fabrics, a directional "pump" layer underneath a distinct windproof and water-resistant outer layer; while effectively completely waterproof against rain, they would fail a strict hydrostatic head test as given in the definition above).

Garments that combine waterproofing with some thermal insulation, such as those manufactured by FurTech and Nikwax Analogy, resist cold bridging, heat transferred through layers of poorly-thermally-insulating materials in close contact that would be prevented by a small airspace.