Kangxi Tongbao () refers to an inscription used on Chinese cash coins produced during the reign of the Kangxi Emperor of the Manchu-led Qing dynasty. Under the Kangxi Emperor the weights and standards of the brass cash coins changed several times and the bimetallic system of Qing dynasty coinage was established. Today Kangxi Tongbao cash coins are commonly used as charms and amulets where different forms of superstition have developed arounds its mint marks and calligraphy. A notable characteristic is that the outer rim on Kangxi Tongbao cash coins on both sides of the coin tend to be quite wide, in contrast to that of the square center hole (方穿, fāng chuān). Apart from the two mints in the capital city of Beijing operated by the central government, many provincial mints operated intermittently. Background After the Manchus occupied Beijing in 1644 the government of the Qing dynasty began the production of the Shunzhi Tongbao (順治通寶) cash coins modeled after the Huichang Kaiyuan Tongbao cash coins (會昌開元通寶錢) of the Tang dynasty and the Dazhong Tongbao (大中通寶) and Hongwu Tongbao (洪武通寶) of the early Ming dynasty. Like these cash coins the Shunzhi Tongbao used mint marks in the form of a single Chinese character on the reverse side of the coin to indicate their origin. Other types of Shunzhi Tongbao were also cast creating a total of 5 different types. Under the Kangxi Emperor only two of these types were retained, one type had a Manchu characters on the left side of the reverse and a Chinese character on the right side of the reverse to indicate the mint of production and was used for provincial mints. And the other type had the name of the mint in Manchu on the right side with the character "" (Boo) on the left which were used for cash coins produced at the Ministry of Revenue and Ministry of Public Works. History In the year Kangxi 1 (or the Gregorian year 1662) all provincial mints in the Qing dynasty were closed down with the exception of the Jiangning Mint. Meanwhile in Kangxi 5 (1667) all provincial mints would re-open again but three years later a large number of them would close down due to the high price of copper in China at the time. The Guangzhou Mint in Guangdong started casting Kangxi Tongbao cash coins with a weight of 1.4 Mace (1 mace = 3.73