Government Proof Sets: 1955 – current
United States Mint proof coins are extraordinarily brilliant, with sharp relief and a mirror-like background. Their frosted, sculpted foregrounds give them a special cameo effect. Proof blanks are specially treated, polished and cleaned to ensure high-quality strikes. The blanks are then fed into presses fitted with specially polished dies and struck at least twice to ensure sharp relief. The coins are then packaged in protective lenses to showcase and maintain their exceptional finish.