The machines have changed but the process is the same. Long strips of metal are punched making blanks called planchets. The planchets are heated to soften them, then dumped into a cleansing bath, a mixture of detergents and soaps that include low amounts of acid. Once cleaned they are sent to the coin press to be struck, then counted and stored in mint sewn bags.

Bag marks are caused when coins rub and bang against each other in the mint sewn bags.

This is where the term bag marks comes form.

Of the four minting facilities currently operated by the United States Mint, only two.. Denver, Colorado and Philadelphia, Pennsylvania.. create Business Strike coins, the coins that are circulated for use in daily commerce... Your pocket change.