1 Dollar - Elizabeth II 4th portrait, Proof Sets

The Canadian dollar coin's brass-plated steel composition dates to a 2012 cost-cutting reform that eliminated the original aureate bronze plating — itself a 1987 innovation when the "loonie" replaced the paper dollar. Proof set specimens struck on this substrate represent a production contradiction the RCM has never fully resolved: the same base alloy used for circulation strikes, dressed up with enhanced dies and mirrored fields, making these among the less metallurgically distinguished proof issues in the series.