Tattooing is still illegal in Korea, but that hasn’t prevented it from being part of hallyu, or the wave of Korean popular culture sweeping the world.

Korea’s medical law, which defines tattooing as a surgical procedure, bars anyone but licensed medical doctors from inking art on the skin. This has resulted in a substantial tattoo industry operating without regulatory oversight. Korean tattoo artists work in the shadows in their home country and are increasingly traveling abroad to promote their work, finding that they are welcomed like rock stars in countries where tattooing is legal.

Ryu Ji-hwan, who works at SHARP Ink in western Seoul, estimates he has visited at least 10 countries as a guest artist.

“Many people overseas are already aware that tattooing is still illegal in South Korea. They often see talented Korean tattoo artists on social media and say, ‘Why is it still illegal?’” Ryu told The Korea 토토 Times, before boarding a plane to head off for another tattoo world tour that will take him through three undisclosed European countries over two weeks.

Ryu has been a longtime member of Korea’s underground extreme music scene, best known as the frontman of D-beat noise punk band Scumraid founded in 2011. It was this environment that led him to his life of “crime.”