Eli5: When your credit card doesn’t read at a credit card machine, why does covering it with a plastic bag suddenly make it work?

Question

Had this done multiple time at the register. Card not reading, so the cashier will cover the ribbon or the chip with a plastic bag and YATZEE, it goes through. Why?

In: 407

Answer 1

One more thing to add is, the data on your card is duplicated on more than one section of the card. So covering the damaged areas allow the scanner to only read the undamaged copy of the data.