Waterproof Gore-Tex® is a combination of materials used primarily in outdoor clothing and equipment that allows that piece of clothing to be both waterproof and breathable. It repels water such as rain, snow, river water, etc. to keep the user's skin dry, but it also allows sweat from the user to escape — this is what makes the material breathable — which also keeps moisture away from the body. Waterproof Gore-Tex® is a technology developed and owned by the W.L. Gore & Associates company.
Due to the demanding conditions in which most outdoor clothing will be used, the materials used to make such clothing must be both durable and waterproof. In the past, nylons and plastics were used to keep moisture away from the skin. These materials are effective in doing so, but they are not breathable. Therefore, users would sweat, which would coat skin and then cool, making the users cold and uncomfortable in extreme conditions.
Wilbert L. Gore, Rowena Taylor, and Robert Gore co-invented waterproof Gore-Tex® to meet the demands of outdoor clothing. The waterproof Gore-Tex® system is based on layers: the outer layer of a garment is typically made of polyester or nylon for strength and durability, with the Gore-Tex layer next. This is the waterproof layer, which is made from polytetrafluoroethylene, or PTFE, the same material that comprises Teflon®.
Early models of Gore-Tex® rainwear stopped there. However, users found that the waterproof Gore-Tex® layer could be easily damaged by sweat and grime, so subsequent models of the rainwear featured an inner protective polyurethane layer to keep the damage from occurring. Some waterproof variants also feature an inner layer made of a softer, more comfortable material, but this does not contribute in any way to its breathability or waterproofing. Gore-Tex® fabrics can be replenished after time using a water-repellent treatment that can be applied in a washing machine or by using a spray bottle.
Since then, W.L. Gore has come up with numerous other uses for waterproof Gore-Tex® materials. Medical instruments are often made of the material, as are instrument strings, such as guitar strings. Because guitar strings often collect grime and oils from the user's fingers, Gore-Tex® is effective in preserving the life of the string by keeping the oils and grime away from the string's core. Gore-Tex® cables are also common on bicycles. Shifter and brake cables can collect dirt and moisture very easily, but Gore-Tex® coating can keep cables sliding smoothly through the cable housing to prevent shifting and braking jams or sluggishness.