The AATCC 127 standard test method is used to evaluate the waterproof performance of fabrics, in particular the measurement of their water resistance in a hydrostatic environment by hydrostatic pressure method. This method determines the water resistance of fabrics by applying gradually increasing water pressure on the surface until water permeability passes through the fabric. During the test, the fabric sample is exposed to static water pressure to record the point of occurrence of water penetration. This standard is applicable to all types of waterproof fabrics and is widely used for mass evaluation of outdoor clothing, tents, rain gear and other products. AATCC 127 provides a uniform standard for manufacturers, designers and consumers to ensure that fabrics can provide the required waterproof protection in wet environments.