The ancient Egyptians were known for decorating nearly every available surface, from the walls of temples to the interiors of tombs and every square inch of statues and furniture. But recent scholarship suggests the Egyptians’ penchant for adornment didn’t end here: As Bruce Bower reports for Science News, infrared images of seven 3,000-year-old mummies have revealed an array of hidden tattoos scattered across the ancients’ bodies.

Archaeologist Anne Austin of the University of Missouri, St. Louis, presented research on the tattooed mummies at the annual conference of the American Schools of Oriental Research in late November. Austin and her colleagues found the tattoos on mummified remains unearthed at a site called Deir el-Medina. The still-unidentified individuals were probably artisans and craft workers who helped construct and decorate the elaborate tombs found in the nearby Valley of the Kings and Valley of the Queens.

According to the paper’s abstract, tattooing in ancient Egypt remains poorly understood. The civilization left very little record of the practice, and prior to the Deir el-Medina finds, researchers had only identified six other Egyptian mummies with tattoos.

Per Nature’s Traci Watson, Austin first spotted the tattoos while studying the Deir el-Medina mummies at Cairo’s French Institute of Oriental Archaeology in 2016. She noticed markings on the neck of a headless, armless torso and initially thought they were painted on. After closer examination, however, Austin realized the designs were actually tattoos. Using infrared light to better examine the mummy, she eventually found 30 individual tattoos, many of them invisible to the naked eye due to resins used in mummification.

Further analysis, including imaging conducted this year, helped Austin and her team identify more Deir el-Medina tattoos.

“It’s quite magical to be working in an ancient tomb and suddenly see tattoos on a mummified person using infrared photography,” she tells Bower.

The tattoos’ significance is still up for debate. All of the tattoos at Deir el-Medina have been found on women. This trend, and the variety of markings found, suggests the body art may be associated with women’s roles as healers and priestesses, not simply fertility and sexuality as previously theorized.

The original tattooed woman assessed by Austin has cross patterns on her arms and hieroglyphic-like elements elsewhere. Most of the marks on her body do not appear on other individuals, leading Austin to suspect she played a significant religious role in ancient Egyptian society.

According to Bower, another Deir el-Medina mummy has tattoos of a human eye—a sign of protection still in use today—and a seated baboon on either side of her neck.

The archaeologist says she can find no discernible pattern in the tattoos found to date.

In 2018, a separate group of researchers found the world’s “oldest figurative tattoos” on 5,000-year-old (in other words, pre-pharaoh) Egyptian mummies. As CNN’s Nell Lewis reported at the time, infrared scans revealed the image of a bull and Barbary sheep on the shoulder of an 18- to 21-year-old male who was killed by a stab to the back. A series of “S” shapes was found on the upper shoulder of the female mummy.

Both individuals had been housed in the British Museum’s mummy collection for more than 100 years by the time the tattoos were finally rediscovered. Daniel Antoine, one of the project’s lead researchers, told Lewis that the process of tattooing in ancient Egypt was similar to methods used today, with an artisan tapping a needle dipped in soot into a recipient’s skin. Although many of the tattoos found are now degraded or darkened, Antoine said they were probably once impressive: “[The Egyptians] were very fine craftsmen,” he added, “so I'm sure they would have been very good at tattooing.”

Prior to the 2018 find, Ötzi the Iceman—who died in the Alps around 3250 B.C.—held the title of world’s oldest tattooed individual. His markings were geometrical rather than figurative.

Scholars say the practice of tattooing likely extends much further back than either the Iceman or the Egyptian mummies. Still, finding a well-preserved human canvas older than these specimens will require more than a healthy dose of luck.