Coating painting, the ability to automatically flow into a smooth coating is called leveling. The levelling method is generally to adjust the sample to the construction viscosity, brush it on the already primer template, make it smooth and uniform, and then use a brush in the middle of the film to apply a longitudinal brush mark, observe how long the brush mark disappears, and the film returns to a smooth surface. Generally, it is rated according to the time required for the film to reach a uniform and smooth surface: no more than 10 minutes is good, 10 to 15 minutes is qualified, and the surface of the sample is not uniform after 15 minutes is unqualified.
It can also be done on a larger area of the template. The sample is first painted on half of the template area, and after 10 minutes, the other half of the template is then painted to observe the levelling performance of the two parts of the wet film connection.
