Paper over bad debit card strip makes it work again?

Factual Questions
1

What is happening here?

Both the credit/debit cards in my wallet have started being troublesome. I must have exposed my wallet (or myself!) to a mag field or something, I dunno, but now most ATMs and POS terminals will not read my cards.

But if I take a sales slip out of my wallet and fold it over the card, and then run it thru a POS terminal, then it will work.

What’s the dope on this? Why does this work?

Also, is there a good way to do this trick with an ATM? Some, like at gas pumps, will work if I can “wrap” the card, but what about the old fashioned ones that “swallow” your card?

2

Not sure about the “wrapping” effect, but I’ve seen cashiers do all kinds of things, including:

~ rubbing the card on their hair
~ rubbing the card on a plastic shopping bag
~ rubbing the card on clothing

I’m assuming “static” has something to do with it. Whatever it is, it works.

3

At my Trader Joe’s the other day, my card wasn’t reading so the girl covered the mag strip with the clear plastic that they wrap fresh flowers in, and then it read just fine.

Wierd, and they themselves don’t know why it works, it just does!

4

You could try clear cellophane tape over the strip.