"Rishengchang's name has made its way across the country and abroad," says Yan Ruiping, deputy curator of the museum. It welcomes more than 1 million visitors every year, including heads of states, scholars and business leaders.

The museum has preserved original account books, letters, bills of exchange and seals, all of which mirror the spirit and wisdom of the Shanxi merchants, experts say.

"The seal was a key tool to ensure credibility of the bills," says Lei Yaxian, head of the Pingyao cultural relic bureau. The transactions between individuals and the piaohao were not legally protected at the beginning, so the value of paper money given to clients who deposited gold and silver relied purely on the credibility of the exchange house, Lei explains. The seal served as an anti-counterfeiting measure and laid the foundation for risk control, she adds