Not everyone in uniform who wants to start tattooing gets the approval of their chain of command. Most have to operate underground, turning whatever work space they have into an improvised parlor. When Jesse Vargas got to Camp Leatherneck for his second deployment to Afghanistan in 2011, he found a computer with an internet connection and ordered a tattoo kit online. It arrived two weeks later through the military mail service, and he took it back to the tent where his scout-sniper platoon lived.

“My buddies were like, ‘Do you know how to do this?’” Vargas said. “And I was like, ‘No, but we’re going to learn.’” He started on himself, spending a little more than an hour inking a fist-size, tribal-style sun on the inside of his upper right thigh. Then he moved on to his platoon mates. Whenever the door to their tent opened while he was tattooing, Vargas and the others hid the equipment under their cots. “I guess we could’ve gotten court-martialed, but it was just the thrill of it,” Vargas said. “It’s the things that go on beside the war — ways to decompress on our end over there.” Vargas left the Marine Corps after that deployment and still inks clients at his Houston home.

When Kintz retired from the Navy as a senior chief petty officer in 2008, he moved to Sydney, Australia, his wife’s hometown, and started looking for work. He applied to the police and fire departments, and even the local bomb squad, but each rejected him. So he picked up the yellow pages and started calling every tattoo shop in town. Most, he said, were owned and run by members of local motorcycle gangs.