The first time a breast cancer survivor asked David Allen to tattoo her chest, he refused. He knew the skin had gone through a lot during the surgery to remove the breasts, called a mastectomy, and he was hesitant about using needles on such a sensitive area. But the woman stayed on him for six months, until he finally caved. 

"It was transformative," Allen, a tattoo artist in Chicago, tells The Verge. "It was pretty overwhelming." The woman started weeping after the tattoo was complete, and Allen was moved, too. "There was a change, a transformation afterwards that we didn't expect," Allen says. "It's not often that you get to use your art to help, to transform someone."

That was about a decade ago. Since then, Allen has refined his technique, and used his tattoos to transform a sense of disfigurement a lot of women feel into feelings of beauty. Tattooing images of plants and flowers over the scars also help women feel like they're taking control of their bodies again, Allen says. He wrote about his experience with cancer patients in an essay published today in the journal JAMA.