State Quarter Proof Sets from the United States Mint are extraordinarily brilliant coins, with sharp reliefs 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 a protective lens to showcase and maintain their exceptional finish. Each of these sets come complete with the outer box and certificate of authenticity as well as no toning on any of the coins.