The invention of the plastic card magnetic stripe has led banks and other financial businesses to implement all kinds of transactions that take the help of the magnet. A magnetic payment card is used for millions of fund transactions per day. Nowadays, magnetic stripes are also used in a number of other cards like membership or identification cards. To read or transfer information from magnetic cards to the respective servers, specialized card readers are constructed.
The history of magnetic cards
Before the magnetic stripe was not used as an information transferring tool, cashiers would write down credit card numbers and send them to the bank for payment. Later, a machine did the job of the cashier (copy embossed numbers) but still, someone had to call the bank to make sure there was enough money on the card to do the payment.
The first credit card came out in 1951. But the magnetic stripe was implemented on credit cards in 1970 which facilitated their usage and their popularity expanded. These days, the plastic card magnetic stripe is used to make about 50 billion times per year.
How does the magnetic stripe work?
The magnetic stripe or magstripe on the backs of payment cards are made of magnetic particles that are similar to iron. The thin magnetic stripe is covered by a plastic film. Each minuscule particles are actually a tiny magnet bar. To the size in perspective, the length of each ‘bar’ is about 20 millionths of an inch.
Each of the tiny bar magnets can be polarized in either north or south. So this works somewhat similar to barcodes, thus opening the gateway for innumerable customizations. This magnetic stripe is similar to the material used as cassette tapes. The difference is you’re using your hand to swipe the card.
The inventor of this technology (IBM) didn’t patent it. Instead, it collaborated with banking and airline technology to promote its standardization so that the technology could be used worldwide.
Some common cards in which the magnetic stripe is used:
- Credit cards
- Debit cards
- ID cards
- Hotel key cards
- Library cards
- Loyalty cards
- Membership cards
The distribution of the magnetic stripe
Up to this point, you might have thought the black line on your credit card is just a single patch. Apart from the tiny 20 millionths of inch divisions, a typical plastic card magnetic stripe is divided into three tracks. Each of them is .110 inches wide according to the ISO/SEC standard 7811. When combined, the tracks have a storage capacity of 1024 BIT. The magnetic cards are provided with a stripe coated with a magnetic metal oxide. Note that each stipe has its unique specifications. They are:
- Track one is 210 bits per inch and contains 79 six-bit plus parity bit read-only characters.
- Track two is 75 bits per inch and contains 40 four-bit plus parity bit characters.
- Track three is 210 bits per inch and contains 107 four-bit plus parity bit characters.
A typical credit card uses only uses the first two tracks. Track three is the read/write track that stores additional information like PIN, country code, currency units.
Types of magnetic cards
There are essentially two kinds of magnetic cards: HiCo (High Coercivity) cards and LoCo (Low Coercivity) cards. LoCo magnetic cards are more common. The writing method used for the LoCo cards uses lesser energy but the data can be erased by strong magnetic fields. But HiCo cards are more resistant and the data does not erase that easily. The lower amount of magnetization used, the easier it will be for the data to get erased and vice versa. Oesterd is the unit of magnetic field strength used to record data on the stripe. LoCo cards use 300 Oe while HiCo cards use 2750-4000 Oe.
Finishing of magnetic cards
A magnetic card can be finished in several materials whether spotlack, structure varnishing, a signature panel, hot stamp.