function Breathable
The term ‘breathable’ is always used in relation to ‘water-proof’ or ‘water-resistant’. Breathability is achieved by pores in the water-resistant coating that are smaller than rain droplets but larger than vapour molecules. A breathable fabric protects the skin from getting wet (and cold), to retain the body heat, but is simultaneously able to release moisture to prevent dampness.
function Breathable
All fabrics are naturally ‘breathable’ and permeable to vapour, to some extent. The small gaps in a knit or weave let air pass through so that perspiration can evaporate. Warm and moist air will always move towards dry and cold air until there is equilibrium, meaning the same level of heat and humidity on both sides of the material. Because the body is normally warmer than the air outside the garment, the heat and perspiration are pushed outwards.
Water-resistant coatings or laminations prevent vapour being transmitted through the material, and the heat and perspiration are trapped inside the garment. ’Breathability’ is achieved by pores in the coating that are smaller than rain droplets but larger than the vapour molecules. A breathable fabric protects the skin from getting wet (and cold), to retain the body heat, but is simultaneously able to release moisture to prevent dampness. The term ‘breathable’ is thus always used in relation to ‘water-proof’ or ‘water-resistant’.