Press hard. You're making copies.

I’m a travel agent. I’m still using a GDS to book airline tickets. The particular one I use was created by United Airlines in 1971. It’s no longer a thing, they’re electronic now, but well into the 2000’s we used to have to issue airline credits as paper vouchers. We’d have to hand write the information on a ticket sized voucher, then run it through a credit card ker-chunk machine to imprint our agency info (embedded in the machines itself) as well as the airline “plate”. The plate was a piece metal the size of a credit card, we had one plate for each airline we had authorization to issue tickets for, and it had the airline logo and 3 digit code on it. You’d put the plate of the airline you were issuing the credit on in the machine like a credit card, then place the voucher on top and run the slider thing over it to make the impression. Top copy was the live voucher, one copy stayed with the agency, 3rd copy was sent to ARC with the weekly settlement. To this day, the airline you issue a ticket on is referred to as “the plated carrier “. Like if a Lufthansa reservation/ticket is issued using a United ticket number, for example, we’d say it was “plated on United”. Even though e-tickets have been a thing for decades now and we don’t use physical plates anymore.