1. There are no obvious pores, bubbles, heap flow and wrinkling on the surface.
2. There is no pitting, impurities, scratches, dirt and uneven coating on the surface.
3. There is no serious leakage, coating peeling, color mixing and adhesion. Do not allow the coating to become brittle and yellow, lose gloss, etc. due to excessive baking.
4. There is no obvious color difference or uneven gloss.