A touch up pen can perform surface treatment on some relatively small and light scratches, covering the marks and making them invisible. The effect is quite good, although it cannot achieve the same effect as the original car paint, it is much better than not repairing at all. Although touch up pens can fill gaps, block contact between air and the surface of the vehicle, and have a certain anti rust effect, they cannot replace professional automotive anti rust paint. The function and usage method of the touch up paint pen are as follows: A touch up pen can perform surface treatment on some relatively small and light scratches, covering the marks and making them invisible. The effect is quite good, although it cannot achieve the same effect as the original car paint, it is much better than not repairing at all. After applying a touch up pen to small scratches or paint peeling areas, the scars can be repaired, covered up, and filled in. The composition of the touch up pen is generally the original car paint. Due to different car models, only specialized touch up pens can be used for different cars.