Proof coins are a special type of coin made by the United States Mint. A newly minted proof coin is an uncirculated coin that has a few differences in its appearance that qualify it as a proof coin. There are a lot of different variables that go into making proof coins, and while many of the steps to making them are also steps used for making business strike coins, proof coins have a few, additional steps in their manufacturing process. All coins from the U.S. Mint are produced when two, separate dies strike a blank piece of metal with tremendous, intensive force. One die is engraved with the front (also called the obverse) design for the coin. The other die has the back (also known as the reverse) coin design on it.
The Steps Used to Make a Proof Coin
First of all, a proof coin is made with a specially polished and treated die to give it the polished, mirror like surface that it has. The key factor is that, by treating the die in a special way, the coins it produces have a different appearance on them. With the technology of the day, the U.S. Mint is able to utilize dies that have been acid treated to cause the high points of the coin to have a specific, bushed look to them. As it is only the high points that receive this look, the backgrounds and low points of the coin retain a smooth, mirror-like finish. This working of the dies gives the finished coin a two-toned look with a frosted appearance on the raise parts of the design and a with a mirror like finish on the background. This contrasting finish is referred to as “cameo.”
The steps for making a proof coin are as follows:
- Blanking. This step involves simply punching the blank coins out of an eighteen inch wide by over a thousand foot long sheet of metal.
- Annealing. This step involves heating the coins to soften them, and washing and drying them too.
- Upsetting is a process by which the coins are run through a special machine to give their edges the raised rim the U.S. coins are known for.
- Striking. This is where proof coin-making processes differ from the regular. Striking involves pressing each blank coin between two dies and impressing the specific designs on them with tremendous force. With a proof coin, only specially treated dies are used to make them, and they are struck twice too. Sometimes, they are struck more times than that even. This gives these coins a very special appearance that is quite pleasant.
- Inspecting. In this step, proof coins are closely examined under a magnifying glass for any imperfections or unstable attributes.
- Counting and Packaging. Once the coins are all approved by U.S. Mint staff, the coins are counted up, put into protective packaging, and stored. The coins are sold as novelties and collectible items, not for the purpose of being used as currency.
The process for making a proof coin is not very different from the process for making a business strike coin. Really the difference only has to do with the metals used (a lot of proof coins are made in silver and other metals than what business strike coins use) and the dies that make the coins themselves. The rest of the steps are quite similar.
Proof coins are quite pleasant and, because of the extra work that goes into making them, often fetch a higher price. Proof coins are intended to be bought and sold for collectors and as gifts. A lot of times, proof coins will be used as commemorative coins, to showcase or hallmark a specific incident or person. These coins are very beautiful and they catch the eye in a special way. Proof coins have been around for a long time, as the Mint started making them in the 1800s, but at this time the technology has changed in such a way that the coins can now truly be made as a cut above the rest.