History of Proof Sets
In 1936, the U.S. Mint produced its first proof set, which included a penny, nickle, dime, quarter and half dollar. The sets were priced at $1.87. No proof sets were produced from 1943 to 1949 and 1965 to 1967.
Annual Proof Sets
Each year the U.S. Mint offers proof sets to the public. Modern proof sets are encased in plastic to protect the coins, which have never been in circulation, and contain one coin of each denomination. Commemorative coins, such as the state quarters, may also be included in proof sets.
Cameo Proof Sets
A cameo proof set is one in which the raised surfaces of the coins appear to be frosted. Unlike the mirror-like field of the coin, the raised surfaces and lettering of the coin appear almost white.
Deep Cameo Proof Sets
Deep cameo proof sets, sometimes noted as "DCAM," have coins with a "black and white" look to them. The mirrored surfaces are so polished that they almost look black, whereas the raised surfaces and lettering are a brighter white than a regular cameo.
Buying Proof Sets
Proof sets may be purchased directly from the U.S. Mint each year. The U.S. Mint even offers a "subscription program" by which you'll be sent new proof sets each year as they become available. Proof sets from previous years can be purchased from reputable coin dealers.