Ventile is a very lightwieght,tightly woven ( windproof) cotton cloth from Britain. The fibers swell to extreme water repellency when wet. There are several different wieghts for different applications. There is another way to view ventile cloth. Look at the performance from inside. Body perspiration will vent around and through cotton and wool fibers.This is what Goretex is supposed to do, and does not. Just remember this is a shell material and must be part of a proper layered outfit.