Carbon-Paper Packets

In the days of the dinosaurs (well, maybe starting in the 1950s when credit cards were invented), merchants in stores and restaurants would use imprint machines when a customer wanted to pay with a credit card. The business would take a carbon-paper packet about the size of a business check consisting of four pages: white (for the customer receipt), blue carbon paper, pink (for the merchant) and yellow (for the bank). He or she would then run the imprint machine over the card to take an imprint of the raised numbers and the customer’s name. If they wanted to check to make sure there were enough funds on the card, or to see if it was stolen, they had to rely on modems, phone calls, or a faxed-based link to contact the bank. Believe it or not, at the end of the day,the merchant would then have to manually enter the credit card information and transmit it to the bank, which would then pay the merchant.

Starting in the early 1990s, carbon-paper packets and imprint machines have been replaced by point-of-sale terminals and payments with smartphone apps such as Apple Pay, Square, and Venmo. With special software, the vendor electronically contacts the credit card’s financial institution for approval, and a receipt is printed or emailed. But it's believed that many businesses still keep an imprint machine and carbon-paper packets hidden in the backroom, just in case their point-of-sale terminal crashes.