system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does wrapping a plastic bag around your credit card help it scan?

Sometimes when my credit card begins to go bad the cashier will wrap a plastic bag around it and magically it will begin scanning properly.  Why does this help?
gpt
Well its not magic, all it does is create an air space between the magnetic strip and the reader. There's an air gap (actually just inert plastic) coated over the magnetic strip in credit cards. With extended use that plastic coating wears away and the strip gets closer to the card reader. Im not 100% on the reason that air gap is important but it has something to do with the reader picking up the right data from the strip.