How to prevent magnetic stripe data from being printed on front of card

I’ve gotten to deal with a couple of different magnetic stripe card reader/writer/printers in my current job, and although they have a lot of similarities to standard laser or inkjet printers, there are a few oddball settings that have to be tweaked to get everything working as it should.

While helping configure a Datacard SP35 card printer for a customer recently, I ran into a weird issue. Windows was able to find the correct driver for the printer, and once we adjusted the print orientation settings, the text printed on the front of the card parallel to the “long” edge. That was good.

What wasn’t good was that an unexpected string of characters also printed on the front of the card. I recognized that that string of characters was the data that should be encoded in the magnetic stripe on the back of the card, but for some reason it was getting printed instead.

It turned out there was one more setting that needed to be adjusted: Mag Stripe Escape Compatibility. We set that to Enabled, printed a new card, and voilà—no more random characters on the front of the card.

(What exactly does Mag Stripe Escape Compatability mean? I have no idea, and haven’t had time to go digging through search results to find something that explains it clearly. If you can give me a succinct explanation, please feel free to leave a comment.)