The ASTM D4400 standard test method is used to evaluate the sag resistance of Coatings. By using a multi-notch coating applicator, the performance of Coatings at different sag resistance levels is tested. This method provides a simple and rapid means of laboratory testing that enables objective rating by observing the sagging pattern of Coatings. Compared to traditional viscosity methods, this method is more instructive for practical application. Suitable for sag resistance testing of aqueous and non-aqueous liquid Coatings.