Proof coinage

Proof coinage refers to special early samples of a coin issue, historically made for checking the dies (as in demonstrating that something is true) and for archival purposes.

Several other methods have been used in the past to achieve this effect, including sand blasting the dies, and matte proofs.

William Wellesley Pole undertook the first rigorous attempt to catalog the coinage of Great Britain and Ireland starting in about 1816.

Starting that year, proof specimens of coins and medals struck at the Royal Mint were produced for preservation.

[3] Gold coins were omitted from proof sets produced for the coronation of Queen Elizabeth II.

1955 saw both the original "box" packaging and introduced the flat-pack, where the coins were sealed in cellophane and presented in an envelope.

Since 1975, the San Francisco Mint has been used almost exclusively for proof coinage, with the exception of the Susan B. Anthony dollar from 1979–81 and 1999, and a portion of the mintage of cents in the early 1980s.

The 2010–2021 proof sets also contain America the Beautiful quarters, depicting different National Parks and Monuments.

Proof sets issued in 2009 contain 18 coins — the most ever included — as that year featured four different reverses for the Lincoln Cent, six quarters issued under the District of Columbia and United States Territories quarters program, four Presidential and one Native American dollar struck that year, and the five cent, dime, and half dollar coins.

Occasionally, there are errors which escape the Mint's inspection process, resulting in some very rare and expensive proof sets.

The design was modified early in the production (reputedly at the request of Jacqueline Kennedy) to give the hair a smoother appearance.

U.S. commemorative and bullion platinum, palladium, gold, and silver coins are also often issued in both uncirculated and proof types, sometimes with different mint marks.

Those produced from 1947 to 1958 (none were made in 1950) were double sets packaged in cardboard holders and have good collector demand.

Finally, individual dealers have made unofficial "year sets", privately packaging all denominations of a certain date.