Citizen Printer

Why would the magnetic strip on a credit card scan; if wrapped in plastic wrap, when it originally wouldn't.

I work at a hotel, and our room charge/key cards often don't scan on the first couple of tries. If we wrap them in plastic wrap, or thermal paper from the receipt printer; most of the time they will then scan successfully. We are scanning them when a guest is making a purchase at a computer/register. We hardly ever have this problem with regular credit cards, just the hotel's cards. Just wondering what is the science involved. Thanks

Public Comments

The magnetic strip on the card is very sensitive to magnets. That's why the reader is tuned very low to avoid damaging the strip. If there's any dirt on it, it won't scan. When you put the paper/plastic, you clean up the magnetic head. Remember tape players? You get the best sound when the head is clean.
This also works on credit cards. Use to do this all the time when I was cashiering. Reason for it, is that most people are careless with their cards and the strip on the card becomes scratched and rough. The plastic bag provides a scratch free surface which makes it easier for the card reader to read.
basically a magnetic reader needs to be able to read magnetic data much like off of a floppy disk, its like you reading a book, if the book is brand new its easy to read, but if i came a long and messed it up, its hard to read, same thing, when you put the paper over it, you are making the surface far less damaged looking to the reader
the strip on the card has been worn out most of the times.... but they are easy to get dmaged and even the material that u keep them in could distort the strip like a certain type of wallet ot purse that u keep them in and soiime studies have also said that keepin them next to a cell phone for a period of time can keep it from working properly. the plastic bag is like temporarily wiping a really bad scratched CD.. the bag becomes a protectant aand at the same time then enough for the cards magnetic strip to be read though it