The terra-cotta warriors buried near the tomb of the first Chinese emperor, Qin Shihuangdi, present a fierce challenge–to modern-day chemists. Since the site’s discovery near Xi’an, China, in 1974, archaeologists have unearthed more than 1,500 of the life-size figures. But once the warriors see the light of day after more than 2,200 years of burial, their paint disappears, sometimes within minutes of exposure.
With an estimated 8,000 more figures still buried, scientists have been looking for ways to lock the paint in place. Now, a group of chemists in Germany has a technique that just might work.