Presidential Dollar Proof Sets by the United States Mint contain the Presidential Dollar Coins for the year minted, including the outer box and certificate of authenticity. Proof coins are extraordinarily brilliant with sharp relief and a mirror-like background. Their frosted, sculpted foregrounds give them a special “cameo” effect, created by the exacting proofing process. Proof blanks are specially cleaned, polished and treated to ensure high-quality strikes. The blanks are then fed into presses fitted with hand-polished dies and struck at least twice to ensure sharp, high relief. Our commitment to you is to offer the highest quality sets at the lowest price online.