There should be only two kinds of people who really understand tattoos at present. One is a tattoo teacher in a tattoo institution. After systematic training and study, he has a good grasp of tattoo technology. The other is friends who have tattooed hairlines (bald people). Tattooing can be used as a way to change their image. If you need to know more, you can ask Mr Chun Wu directly. He has been studying tattoo technology for several years, and many friends have asked him to tattoo his hair.