Cards often contain a magnetic stripe for the purpose of being swipe read in a magnetic (mag) stripe reader to acquire the cardholder data accurately and quickly.
The standards for mag stripe encoding (established in ISO/IEC 7810, ISO/IEC 7811, ISO/IEC 7812, ISO/IEC 7813, ISO 8583, and ISO 4909) define the physical properties of the card, including size, flexibility, location of the magstripe, magnetic characteristics, and data formats. They also provide the standards for financial cards.
The mag stripe card was developed by IBM in the 1960’s. Since the first magstripes were invented they now come in many different types and sizes. There are two main varieties: high-coercivity (HiCo) at 2750 or 4000 Oe and low-coercivity (LoCo) at 300 or 600 Oe. High-coercivity magstripes are harder to erase, and therefore are appropriate for cards that are frequently used or that need to have a long life. Low-coercivity mag stripes require a lower amount of magnetic energy to record, and hence the card writers are much cheaper than machines which are capable of recording high-coercivity magstripes.
A card reader can read either type of mag stripe, and a high-coercivity card writer may write both high and low-coercivity cards (most have two settings, but writing a LoCo card in HiCo may sometimes work), while a low-coercivity card writer may write only low-coercivity cards.
In practical terms, usually low coercivity magnetic stripes are a light brown color, and high coercivity stripes are nearly black. There are exceptions of course including newer proprietary mag stripe color formulations. High coercivity stripes are resistant to damage from most magnets likely to be owned by consumers. Low coercivity stripes are easily damaged by even a brief contact with a magnetic purse strap or fastener.
Magnetic stripe cards are used in very high volumes in the mass transit sector, replacing paper based tickets with either a directly applied magnetic slurry or hot foil stripe. Slurry applied stripes are generally less expensive to produce and are less resilient but are suitable for cards meant to be disposed after a few uses.