A female portrait of Qing Dynasty(1644-1911). [Photo by Jiang Dong/China Daily]

"But many scholars remained skeptical about when it was produced because its thick body, which was shaped into an elegant form, was different from other artifacts from the reign," Jingdezhen Ceramic Archaeology Research Institute researcher Jiang Xiaomin says.

Only five of such items are known to have survived, four of which are housed in the Palace Museum.

Experts had long disputed whether the reign mark was reliable, but shards of a press-hand cup unearthed in Jingdezhen in 2018 from an archaeological stratum of the period of Yongle's reign has finally answered the riddle.

This exhibition marks the first time for this precious piece to be exhibited publicly.

If you go

9 am-5 pm, last entrance at 4:30 pm. Closed on Sundays, through Sept 12. Online reservation needed. Poly Art Museum, 9/F, New Poly Plaza, Chaoyangmen Bei Dajie, Dongcheng district, Beijing.010-6500-8117.