(Westend61/Getty Images) Humans have been tattooing themselves for thousands of years, for spiritual, cultural, or personal reasons. Long before we were covering ourselves in ironic stick'n'pokes, ...

Rachel Feltman: Nearly a third of U.S. adults have tattoos, so plenty of you listeners can probably rattle off the basic guidelines of tattoo safety: Make sure you go to a reputable tattoo artist who ...

John Swierk is an assistant professor of chemistry at Binghamton University, State University of New York. Tattoos are an incredibly common form of permanent self-expression that date back thousands ...