Automobile solar film has a "texture" and is directional. In the production process of automobile solar film, there will be slight stretching and stress in the natural direction. When the baked film is heated, stress relaxation occurs, that is to say, the film shrinks along the stretching direction. It is through the contraction of the film that we shape and adapt to the shape of glass. The key is to remember that only the "finger protrusion" perpendicular to the natural direction can contract. In most cases, when the rear windshield is attached, the position of the window film on the glass is the same as the natural direction, so that all the shrinkage occurs on the upper and lower sides (top edge and bottom edge) of the glass. Turn on the baking gun, adjust the temperature from medium to high, and the distance to the film is 8 ~ 10 inch (the distance varies according to the temperature of the baking gun). Move the baking gun horizontally along the finger protrusion until the pattern wrinkles appear, and smooth the film by hand. Remember that the "shrinkage" of the film is limited, and it cannot always be baked in one area. It is easy to touch the film by hand, mainly for the following two reasons: it is not easy to wrinkle when touching the film by hand, but it is easy to control and separate the finger protrusions; In the process of baking the film, I have a direct feeling about the changes of the film.