"GB 9273-1988 Paint film imprint-free test" is a standard used to evaluate the degree of coating drying of Paints, varnishes or related products. This standard adopts ISO3678-1976 international standard, which stipulates whether the coating can reach the "imprint-free" state under specified conditions by applying a piece of polyphthalamine wire mesh and rubber round plate to the coating surface. The test includes the coating application method, drying conditions, the provisions of the applied force, and the necessary measurement steps and reporting requirements. It is suitable for glass plates, steel plates, tack iron plates and other test plates, and requires that the painting and measurement comply with the relevant provisions of GB 9271 and GB 1764.