HOW did a 32-year-old college dropout from the bayou of Louisiana, with no formal training in art — well, to be frank, no training at all — end up with a one-man show in a New York gallery and a client list that includes Robert Downey Jr. and Orlando Bloom?

For Scott Campbell, it all started at a tattoo studio in the Lower Haight district of San Francisco. “I’m just the dirty kid who snuck in the back door,” said Mr. Campbell, who said that he got the bulk of his art education tattooing teenage gang members in San Francisco in the 1990s.

Scott Campbell’s took off in 2005, four years after he moved to New York and opened his studio, Saved Tattoo, in the then-emerging neighborhood of Williamsburg, Brooklyn.

One day an impatient Australian came in and commissioned a small bird in flight on his left forearm. The next day, Mr. Campbell said, “Entertainment Tonight” came with cameras, grilling him on what kind of tattoo he had just given Heath Ledger. The two became friends — “the sweetest guy, so open,” he said of Mr. Ledger. “The third time I hung out with him, I had keys to his house.”

It became a pattern, as Mr. Campbell became something of a celebrity tattoo artist, charging as much as $300 an hour ($1,000 minimum) to ink customers like Courtney Love and Josh Hartnett. After Mr. Campbell tattooed three of Sting’s adult children, he said, the singer and his wife, Trudie Styler, put him up at their house in London when he was there for a gallery show in October (he said he paid Sting back by giving him a tattoo, a meditation labyrinth on his back). And he said he recently went gallery hopping with Marc Jacobs, who sports a tattoo of his two bull terriers on his shoulder, courtesy of Mr. Campbell. The nature of his craft, he said, helps to explain these friendships. “Tattooing is a very intimate exchange,” he said.

“You have your hands on someone, you’re communicating with them, and they’re very yielding,” he continued. “There’s no cool-guy factor, no barriers.”