Breathability is the ability of a fabric to allow moisture vapour to pass through it. It is an essential contributing property to thermal and Physiological Comfort in clothing, and is vital in filtration and medical textiles.
Waterproof-breathable fabrics are a highly competitive market, where Gore-tex? reigns supreme, though several new fabrics have recently emerged that aim to usurp its position. There are numerous laboratory testing methods for determining breathability, and none correlate perfectly with human trial testing. This leads to problems in determining which fabric is ‘most breathable’, as the properties of each fabric will vary according to the testing method used.
Breathability is crucial in many areas of textiles, but particularly in clothing, as an impermeable wet garment will lead to garments becoming saturated by sweat. Wet garments conduct heat away from the body 25 times faster than dry garments do. In addition, wet skin feels uncomfortable: it has been shown that Physiological Comfort is directly related to skin wettedness.