Because putty is the base filling material, the paint film is connected with the most base wall by using putty as an intermediary substance. As the ancients said: "If the skin does not exist, the hair will be attached". Paint film and putty are like the relationship between hair and skin; without skin, hair naturally loses its foundation of existence; without putty, paint film also loses the prerequisites for attaching to the wall. Therefore, putty is more important than topcoat in a sense. It directly determines the overall performance and overall decorative effect of the topcoat after film formation, and also affects the level of indoor pollution.