The ancient army that's still growing

In Pit 1, behind rows of warriors, archaeologists compile a detailed file for each soldier that is brought to light. [Photo by Fan Zhen/China Daily]

The breakthrough

Many of the colors were lost, either in a suspected arson attack by peasant forces at the empire's demise, or during the army's 2,000-year subterranean sojourn. The sections that survived fire and age were probably ruined by Xi'an's arid atmosphere when they were uncovered during the excavation.

"When fully exposed to dry air, the lacquer begins to curl after about 15 seconds and flakes off in about four minutes, permanently taking the precious traces of crimson, purple and white with it," Zhou said.

"Between the early 1980s and the mid-90s, we tried everything we could to retain the moisture inside the lacquer layer and stabilize it, but in vain."

The breakthrough came around 1995, when the team decided to experiment with a material used in the preservation of ancient lacquer furniture. "It's a zillion times more complicated than it sounds," Zhou said, adding that the many failures on the road to success had been an emotional roller coaster.

"'Breakthrough' may not be the right word. In research and protection, we only move forward by an inch a day," the 56-year-old said.

Some of the newly restored warriors will be on show at the museum until March, as part of an exhibition called, "Terracotta Warriors: True Colors". In a sparsely decorated, dimly lit hall, the faint colors - be it a blush on the cheek or a swirl on a hemline - are illuminated by spotlights, and they tell a long-forgotten story. The face of one figure, believed to represent an army sorcerer, bears a distinct green tint. It's a place where history can echo in a child's imagination.