Gore-Tex is a registered trademark of W.L. Gore & Associates, best known for its use in relation to waterproof/breathable fabrics.

Gore-Tex materials are typically based on expanded polytetrafluoroethylene PTFE and other Fluoropolymer products. They are used in a wide variety of applications such as high performance fabrics, medical implants, filter media, insulation for wires and cables, gaskets and sealants.

Gore-Tex material is composed of a thin, porous fluoropolymer membrane, bonded to some fabric, usually nylon or polyester. The membrane has about 9 billion pores per square inch, making it impenetrable for liquid water while allowing the water vapor through. The result is a material that is waterproof and breathable. The outer fabric is additionally treated with water repellent.

The best known application for Gore-Tex fabrics is in outdoor activity clothing. The structure of the fabric forms an effective barrier against wind and rain, while still allowing water vapour to pass through. This helps to keep the wearer warm and dry, while the breathability allows sweat to escape.

The first commercial consumer product using Gore-Tex was a tent called the Light Dimension that was created and sold by the Seattle firm, Early Winters, Ltd., in 1976.

Gore requires that all garments made from their material have taping over the seams, to eliminate leaks. This requires special machinery. The fabric is not available on open market, and is exclusively licensed for specific manufacturers, to maintain the highest quality control.

Gore's sister product, Windstopper, is similar to Gore-Tex in being windproof and breathable, but is not waterproof.

You can visit the Gore-tex official web site at http://www.gore.com