The paint pen is a paint pen, and there is one inside. You can hear the noise when you shake it. Writing on the surface of an object has a little protruding feeling and is very textured. The written font is very beautiful. As long as the material of your schoolbag does not fall off, it will not fade. Just like an iron gate, the paint on the surface of the iron gate will fall off after oxidation, but it will not fade.