National Park Quarter Proof Sets by 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. We carry the U.S. Mint Proof Sets, which all come with the U.S. Mint issued box and certificate of authenticity. Our commitment to you is to offer the highest quality sets at the lowest price online.