In the tang dynasty, the currency was "two" as a unit of calculation, mainly five, two, two, twenty and fifty-two. In the form of "collar", "wat" or "cake" as the name of the number, the majority of silver in silver is cast into the shape of a silver collar or silver cake. Among them, "collar" is the main form of silver at that time. The silver collar can be divided into two types: straight body and girdle
The silver collar of tang dynasty can be divided into tax silver, near yinyin (also known as "gongyin") and inner bank, etc. The tax is levied on businessmen, including tax merchants, silver, silver, grottoes, tintin, silver, and silver, and silver, etc.
Tang dynasty silver collar "silver collar" as the main name, have begun to book inscriptions carved on the silver collar or ink, content, weight, years, casting department, people involved responsible official position in silver source, and the name of the name, craftsmen, etc.
As long as the silver ingot, the tang dynasty is called the "collar" and "wat" is the handboard, which is used as a unit of money. In the tang dynasty, the size of the silver collar was different, but the shape was almost the same.