 However, due to monetary problems such as enormous local variations in monetary supply and exchange rates, rapid changes in the relative value of silver and copper, coin fraud, inflation, and political uncertainty with changing regimes, until the time of the Republic payment by weight of silver was the standard practice, and merchants carried their own scales with them.Most of the so-called "opium scales" seen in museums were actually for weighing payments in silver.The tael was still the basis of the silver currency and sycees remained in use until the end of the Qing Dynasty.