"Emperor Taizong (Zhao Jiong) once sent people to seek out and purchase masterpieces of calligraphy from the past. … The rubbings made of them were given only to his cabinet ministers," wrote the Qing emperor. "A copy that was precious back then is priceless today.

"If not for it, I wouldn't have the chance to experience any of the brilliance that delights my heart now."

While Kangxi's words can be viewed at the Palace Museum exhibition, the collection of rubbings for which the writing was intended as a colophon didn't last. In October 1860, right in the middle of the Second Opium War, invading Anglo-French troops ransacked and burned Beijing's Old Summer Palace, the once magnificent royal garden retreat where the collection had been housed.

But that was not really the end. Even during the Song era, recut stones and copies of the collection, two of which are on display at the ongoing exhibition, had already been made. In 1769, Emperor Qianlong (1711-1799) ordered the making of recut stones based on the much-treasured early version of his grandfather, Emperor Kangxi. Although the stones, also housed at the Old Summer Palace, suffered a similar fate in 1860, many of the rubbings that had been taken of them have survived.

"On top of that effort, Emperor Qianlong, with his own immense hubris, oversaw the making of another huge collection of rubbings titled Model Calligraphy of Sanxi Hall, after his own study room inside the vast palatial complex that is today the Palace Museum," says Feng.

"It was the biggest collection of calligraphy rubbings ever produced in Chinese history."