Would a plastic sleeve protect a hotel key card from demagnetizing better than a paper card sleeve?

Question

The cheap LoCo 300 Oersted key cards at hotels typically get demagnetized by everyday electronic devices--particularly cell phones. This I know for sure.

But does the paper sleeve that the key card comes in protect it at all? Or would a plastic--or some sort of anti-static type of sleeve--offer more protection from the magnets inside these devices?

Answer 1

Neither!

300 Oersted is quite low magnetisation, and common level for Credit cards and so on (I have worked on security cards with 3000 O!).

Even though, to demagnetise a card, just passing a magnet (like the busters did) DOES NOT erase the card!  To erase a card, you need an ALTERNATED magnefic field going from high to low intensity.  I doubt that even a cell-phone has this "feature" or ability (except, MAYBE, a particular set of circumstances).

What happens most of the time is that some scratch takes off some of the magnetic powder from the card, removing "some" data: the card becomes unreadable (or there is an error of just 1 bit...)

Protection? PHYSICAL protection of the strip from scratch is the solution to look for (a sleeve with soft interior and hard exterior?)

EDIT:

It means your hotel cards are very, very low magnetisation.

Cell-phones, in fact, generate magnetic fields (the transponder stage), and this might wipe out the cards.

I have no solution for this, since ...

WELL, thinking of it: a FARADAY CAGE!  A small sleeve made of a copper GRID (the tiniest mesh the better), that folds around the key and THAT will short magnetic fields!

Answer 2

neither, magnetic fields can pass through both

Answer 3

In all the hotels I have ever stayed in over the years that have key cards and shoved them in my pocket with keys, cell phones, thumb drives, change, defensive devices, you name it, Not one has ever been demagnetized.

Watched a show on MythBusters about wallets that people said wiped out their credit cards.  BUSTED.

I have not been handed a sleeve in years.  Just the jacket with the room number, coupons and my room number.

Either way, I can't imagine a little piece of paper protecting the card from a magnet.

Answer 4

Anti static might, but plastic is more likely to wipe it as it will also build static. For such a location you would be better using hi-co, or better still proximity cards. They tend to work out cheaper overall as they do not fail so often, are not prone to external damage, and the readers last almost forever.