 Common weights were 50, 10, 5 and one tael.Before the year 1840 the government of the Qing dynasty had set the official exchange rate between silver sycees and copper-alloy cash coins was set at 1000 "wén" for 1 tael of silver before 1820, but after the year 1840 this official exchange rate was double to 2000 "wén" to 1 tael.During the reign of the Xianfeng Emperor, the government of the Qing dynasty was forced to re-introduce paper money, among the paper money it produced were the Hubu Guanpiao (戶部官票) silver notes that were denominated in taels.