There are many training institutions, large and small, with different technical levels. Due to the lack of professionalism, the whole teaching level can't keep up. There are also many institutions that offer short-term crash courses, such as promising to learn this technology in two or three days. Without professional training and systematic study, you can't learn at all, at least you can't learn well, and the graduated tattoo artist's level is certainly not much higher.
When choosing a school, we need to look at the school's qualifications, popularity, teachers, school environment, large class or small class teaching, and then choose a school after comprehensive analysis of the school's situation.