In 1663, a new gold coinage was introduced based on the 22 carat fine guinea. Fixed in weight at to the troy pound from 1670, this coin's value varied considerably until 1717, when it was fixed at 21 shillings (21/-, 1.05 pounds). However, this valuation overvalued gold relative to silver compared to other European countries. British merchants sent silver abroad in payments while exports were paid for with gold. As a consequence, silver flowed out of the country and gold flowed in, leading to a situation where Great Britain was effectively on a gold standard. In 1816, the gold standard was adopted officially, with the silver standard reduced to 66 shillings (66/-, 3.3 pounds), rendering silver coins a "token" issue (i.e., not containing their value in precious metal).