Researchers have used lasers to uncover highly intricate designs of ancient tattoos on mummies from Peru. The preserved skin of the mummies and the black tattoo ink show a stark contrast. They reveal fine details in tattoos dating to around 1250 A.D. that aren’t visible to the naked eye. Scientists examined around 100 mummies from coastal Peru’s Chancay culture. All the individuals had some form of tattoos on the back of their hands, knuckles, forearms or other body parts. The findings were published Monday in the journal Proceedings of the National Academy of Sciences.