Regarding the choice of protective film viscosity, its basic principle is that the viscosity is appropriate. In layman's terms, it is because different surfaces require different viscosity. In this way, we can observe the viscosity rise speed according to the difference of the surface and pressure. In this case, we need to leave the protective film for a long enough time before peeling it off, so that we can determine whether the viscosity of the protective film is appropriate. We need to know that regarding the protective film, it uses a rubber or acrylic protective film, and the effects of the two are different. In this case, the rubber is relatively soft, but for acrylic, it is relatively hard, so when we choose, we generally consider the rubber type protective film first, and then the acrylic type protective film, which is practical for us In terms of processing, given a surface, at this time we have to choose the appropriate glue and viscosity. Here, we should pay attention to the low-viscosity protective film if the surface of the protective film is smooth, and the medium-viscosity protective film for the medium rough surface.