Regardless what materials it selected, before painting hood lacquer, it must go through a special processing on the surface of the body. This processing, on the one hand is to strengthen the firmness of skeleton, in order to reach the purpose of no distortion; the other is to ensure the hood lacquer and lightless lacquer can firmly grasp the substrate of the body, to prevent the peel off of lacquer layer and substrate, this process is called “Work Ground”. "Work" means process and manufacture; “Ground” refers to a series of processes for hood lacquer and sculpture, of which is carried out in the ground of lacquer, so it also be called as painting ground or plastering ground. again for the paint to the child, gray to son.