When the dynasty entered its final century, Ming emperors' ostentatious aesthetic preferences produced porcelain with exotic colors and lines, and perfunctory portrayals of dragons.

"The business-based urban economy boomed at that time," Wang says.

"Even imperial porcelain items were then contracted to privately owned workshops in Jingdezhen under government supervision."

But every era has its exceptions. A blue-and-white press-hand cup (a heavy vessel small enough to fit in the palm of a hand) with a flared rim and deep rounded sides is a signature item believed to have belonged to emperor Yongle-the first emperor to live in the Forbidden City-as is indicated by the marks on their bases.