The purpose of this standard is to evaluate the performance of coatings such as Paints and varnish on a strictly specified substrate over a large area, including brushing and flowability. The standard requires that the coating be applied to the test plate, and the performance of the coating on the raised parts such as the edge, the rivet head, and the weld is observed to evaluate the hiding power and protection ability of the coating. The test includes detailed steps such as plate selection, preparation, and painting procedures, which need to be compared according to the actual situation and the standard reference paint sample. The results are subjective, so the evaluation should be carried out in combination with the standard and practical application requirements.