Although high inflation is associated with the spread of paper monies, rapid price increases are well known under the metallic standard from several countries, caused by the debasement of coins. The exact mechanism is still a puzzle. If agents were rational, why did they accept inferior coins at par with better ones? This paper compares five debasement cycles that occurred in Sweden-Finland 1350-1594. During the initial phase of such cycles coins tended to circulate by-tale, while by-weight circulation was most common towards the end of the cycles. A premium on the heavier coins implied that they were not driven out of circulation. The seignorage rate was significant during the initial phases of the cycles, while it decreased when prices and exchange rates adjusted in response to the debasement, prompting a recoinage, when the monetary unit was strengthened. It is this shift from by-tale to by-weight circulation that explains the high inflation rates that could occur before the rise of paper money.
