2. Deformation size. Place the porcelain piece on a flat platform, move in all directions to check whether it is stable and well-balanced, whether the mounting surface and the edge of the porcelain surface are level, and whether the mounting hole is even and smooth.
3. Glaze quality. The glaze must be delicate and smooth, with uniform glaze color. The visible surface, especially the glaze quality that can be splashed by water, is particularly important. Put a few drops of colored liquid on the glaze surface and wipe it with a cloth. After a few seconds, wipe it dry with a damp cloth. Check the glaze surface. It is better to have no dirty spots.