The AATCC 35 standard test method is used to evaluate the waterproof performance of fabrics under simulated rainfall conditions. This test evaluates the ability of fabrics to resist water permeability under a certain pressure by simulating the environment of actual rainfall. During the test, the fabric sample is subjected to water flow equivalent to a certain intensity of rainfall to evaluate its surface waterproof performance and the time and degree of water penetration. This method is widely used in the performance inspection of outdoor clothing, rain gear and Miscellaneous Water proofer. AATCC 35 provides a standardized test method for products to ensure that they have sufficient water resistance in the actual use environment to meet the needs of consumers.