Intricate ancient tattoos revealed by shining lasers on mummies

The intricate details of tattoos inked more than 1200 years ago have been made visible by scanning South American mummies with lasers.

The mummies, belonging to a pre-Hispanic people known as the Chancay, were found in 1981 at the Cerro Colorado cemetery in the Huaura valley of Peru.

While it was clear to the naked eye that many of the 100 mummies were tattooed, the ink had bled beyond the boundaries of the original designs and also faded, making it impossible to see what the original markings would have looked like.

In a new study, Michael Pittman at the Chinese University of Hong Kong and his colleagues ran lasers over the specimens in a dark room and took long-exposure photographs. The lasers caused the skin to glow brightly, producing a stark contrast with the non-fluorescent tattoo ink.

This technique, which causes no damage to the mummies, has never been used on tattoos before. Importantly, it shows not just where ink is on the surface but also in the deeper layers of the skin, says Pittman.

“This helped us to see past the bleed accumulated over the lifetime of the tattoo’s owner to reveal the finer original design of the tattoos,” he says.

The researchers believe the tattoos are so fine that they must have been made using a needle and ink technique with a cactus needle or sharpened animal bone, rather than a “cut and fill” method.

Tattoos seem to have been important to the Chancay, says Pittman, as they are found on a large proportion of known mummified human remains.

“Many of the designs, geometric patterns featuring triangles and diamonds, are shared in their other artistic media too such as pottery and textiles, and some pottery human figures even show geometric tattoo designs,” he says.

Some of the tattoos seem to have required special effort due to their intricate designs, while others are small and simple. “So, to some extent, ancient Chancay tattoos show a lot of parallels to the variation in design and significance we can observe among tattoos today,” says Pittman

Pittman says many traditional tattoos made by other ancient people could also be viewed in detail using the laser-stimulated fluorescent technique. “We therefore plan to apply the method to other ancient tattoos from cultures around the world to try and make other interesting discoveries,” he says.