MICR

12/21/2008

MICR-Magnetic Ink Character Recognition. A technique for identifying and sorting documents printed with ink containing tiny magnetizable particles. The particles are magnetized by a magnetic field and are moved past a set of read heads that allow a limited set of characters (digits 0-9 and a few separators) to be recognized by comparing the relative widths of various parts of the character. MICR was devised in the 1950s and is most often used to create a machine readable band at the bottom of checks, utility bills, and similar documents.

MICR toners are available for laser printers. They are more expensive than conventional toners. It is important that the toner be matched to the fuser if one expects the ink to bond to the paper and not to the fuser roller or to neither.

MICR inks are not currently (2008) available for inkjet printers. The magnetic field associated with the heaters used to propel the ink would interact with the magnetic particles in the ink and prevent normal ink flow.

Many bank and other MICR users have switched to optical reading of the MICR characters. However, many -- including the Federal Reserve System that routes checks in the US between distant points -- have not. Although MICR fonts are available for non-MICR printers, it is probably not advisable to print MICR information with non-magnetic ink unless it can be assured that it will only be processed by optical equipment.