The NF T30-087-1-2009 standard defines a drying test method for paints and varnishes to evaluate the drying state and drying time of coatings under different conditions. The standard is divided into two parts. The first part focuses on how to determine the drying state of coatings through specific experimental procedures, including the distinction between dry and completely dry surfaces, and the determination of relevant time. This standard provides Coating manufacturers and testing laboratories with a scientific, standardized drying evaluation method, which helps to ensure the performance and mass stability of Coatings. It is widely used in the quality control process of paints, varnishes and other products.