When I was a kid every store had a small metal machine that they would use to run credit cards. The cashier place the credit card on the metal surface, then overlay it with a piece of carbon paper. Then the cashier would slide the top metal piece across the paper to imprint the card number. Grandpa worked at Wells Fargo for as long as I could remember, and he gave me one of those credit card machines when I was younger. I wish I still had it.