Each square inch of a GORE-TEX membrane contains nine billion pores, making it a scientific feat for the geek at heart.
The GORE-TEX membrane contains nine billion pores per square inch of fabric, making it a scientific feat for the geek at heart."
For pioneering mountaineers in the pre-GORE-TEX brand era, wearing layer upon layer of wool wasn't a sustainable or convenient solution. The need for something better in the marketplace made the entry of GORE-TEX product technology a welcome one. When considering all that the membrane makes possible, it's important to note its coincidental inception. It was Bob Gore's frustration that led to the accidental discovery of this material in 1969. Uncovering the core ingredient of the GORE-TEX membrane was actually just a fortunate accident. Fast forward to today — GORE-TEX product technology enables millions of adventurous explorers to push the boundaries of what's possible. This special membrane keeps water out, but simultaneously enables sweat to evaporate. Take a closer look. Here are a few of the key facts that make the GORE-TEX membrane so remarkable: What makes the membrane waterproof? Wet fabrics steal warmth from your body, conducting heat away three times faster than dry clothes. Each microscopic hole in the membrane material is 20,000 times smaller than a water droplet. As a result, it's impossible for snow, sleet, rain and snow to pass through. In addition, all GORE-TEX garments have a Durable Water Repellent treatment applied to the outer layer, which helps water bead up and roll away. What makes the membrane breathable? Unlike technical garments made from waterproof rubber (like rubber boots), the pores within the membrane are 700 times larger than a water vapor molecule—large enough to let sweat vapors seep out (while still keeping water out). Whatever the climate, the risk of overheating is mitigated by this facet of the technology. What makes the membrane windproof? Cool wind causes heat loss, which naturally leads to a decrease in body temperature. Each GORE-TEX garment is put to the test in a Storm Cube, which can be cooled to 39 degrees with winds up to 32 miles per hour, to ensure permeability is less than 1.0 cfm (the volume of air that can pass through one cubic foot per minute). 
Of course, it's no surprise that it requires a "can-do" entrepreneurial spirit to continually challenge the norms of what seems possible. While the GORE-TEX fabric catalog is vast, the membrane still reigns as the brand's most important discovery. It's at the heart of each and every product.
