How Does Magnetic Ink Work With Printers?

Why Magnetic Ink?

Magnetic ink contains iron oxide, which allows it to take a magnetic charge. Magnetizing the letters and symbols printed with magnetic ink allows for Magnetic Ink Character Recognition (MICR), which is widely used in banking. MICR characters can be read by a character recognition system regardless of writing or other marks that would obscure the characters to an optical recognition system.

Cartridges

A MICR toner cartridge must physically be of the same form factor and design as an OEM printer cartridge for the printer you intend to use. Some printers are specifically designed for MICR printing and designated companies make MICR toner cartridges for these printers. Other printers were never designed for MICR use, but printer cartridges may be refilled with MICR toner and then used in your printer. When choosing to use a remanufactured MICR cartridge in your printer, it's important that you choose a cartridge in which the original drum has also been replaced with a new one. Damage to a printer drum can leave spots or streaks of ink on whatever you print. A spot of MICR ink in the wrong place on a check may cause the magnetic character recognition system to read a decimal point where there shouldn't be one.

Printing and Reading

MICR ink works just like any other ink or toner in the printing process. In a laser printer, the MICR toner is polarized and then fused to the page. MICR characters are magnetized such that the negatively charged pole of each character is on the right. A magnetic character recognition system reads these characters with a MICR read head. The principle is the same as the read head in an audio or other magentic tape player.