How to measure the breathability (r.e.t.) of a material?
The breathability of a material is its capacity to eliminate the water vapour generated through perspiration. During intense physical exercise, highly breathable clothing is therefore essential to avoid staying wet. Breathability is measured in terms of it Evaporative Thermal Resistance (R.E.T.) coefficient. It measures the resistance of a fabric to the evacuation of moisture. The lower the resistance (hence, the lower the coefficient), the more breathable the fabric!