Due to differences in the milling and annealing process, the Canadian variety of the 1981 20-cent coin is distinctive to attentive collectors and even cash handlers. The top and bottom edges of the milling is rounded over, not squared like the Australian and London varieties, and despite being in circulation for well over 25 years, even when well worn, the fields remain shiny, and not dulled like those produced at other mints. These qualities are also observed in Canadian coinage of similar ages.