"ASTM D 4400-1999 Determination of sag resistance of coatings with a multi-notch coating applicator" is a laboratory test method used to evaluate sag resistance performance of aqueous and non-aqueous liquid coatings. The standard observes and objectively rates the sag phenomenon of coatings by applying coatings on vertical surfaces with a multi-notch coating applicator. It consists of two procedures: Procedure A for coatings of any type or Color, and Procedure B for non-dark coatings. This method is simple and fast, and can provide quality control basis for Coating manufacturers and buyers to help optimize Coating formulations and ensure the appearance and performance after coating.