Swedish plate money

Swedish plate money, known as plåtmynt, consists of large, rectangular sheets of copper minted as currency by the Swedish Empire. Counted among the heaviest currency objects ever issued, these unwieldy plates were introduced because Sweden possessed abundant copper mines but suffered from depleted reserves of precious metals such as silver. Copper daler currency had been minted from 1624, and upon reaching maturity at the age of eighteen, Queen Christina began issuing plates weighing as much as fifteen kilograms to serve as legal tender.

Because of the low intrinsic value of copper, considerable quantities of metal were required to meet face value. The largest pieces were denominated at ten daler and weighed nearly twenty kilograms (forty-four pounds). The cumbersome size and extraordinary weight of plate money created significant practical difficulties in circulation, which eventually prompted Sweden to become the first European country to issue banknotes via Stockholms Banco in 1661. Plate money was briefly abolished at the end of July 1768, only to be reintroduced on 4 August out of necessity, remaining in circulation until 1776. In the modern period, the wreck of the Nicobar has provided many surviving examples.

These thick rectangular copper pieces are characterised by impressed stamps applied to their surface, which record the regnal arms, the year of issue, and the monetary denomination. Values stated in copper currency were marked with the abbreviations K.M. or KMT, whereas denominations tied to the scarcer silver daler were denoted by S.M. or SMT.