100 Mil Réis Thesouro Nacional, Copper exchange note

Brazil's Imperial Treasury began issuing copper exchange notes — cédulas de cobre — in 1833 as a direct response to a chronic shortage of small-denomination copper coinage in circulation. The notes were explicitly redeemable for copper coin, not silver or gold, which placed them firmly at the bottom of the monetary hierarchy and made them deeply unpopular with merchants, who regarded copper itself as a debased medium.

The series predates the Banco do Brasil's later note-issuing monopoly and reflects a period when the Treasury was improvising monetary infrastructure for a country barely a decade into independence. Surviving examples are rare; most circulated heavily and were redeemed or simply disintegrated.