Magnetic ink character recognition, often abbreviated as MICR, is a method of computerized reading. Computers detect magnetized metals in the ink of the characters and determine their sequence from the spacing of the ink. Magnetic ink characters are often used on bank documents, including checks, and the blocky numbers are commonly associated with the concept of advanced technology. The use of these characters provides banks with a highly accurate and efficient way to sort documents and input data.
The most important component of the ink used to create the characters is a powder that has the potential to be magnetic. Usually, iron oxide powder is used to make the ink for printing the characters. When the characters are about to be read, the paper passes through a strong magnet, which magnetizes the iron oxide in the ink. Next, a reading head runs over the characters and detects the pattern of the magnetic forces. This is similar to the way in which computers use reflected light patterns to read barcodes.
Special fonts that produce distinctive patterns were developed specifically to be used in magnetic ink character recognition. There are two fonts primarily used for this process around the world: E-13B is found on checks in the United States, the United Kingdom and India, while documents in some other nations have characters in the CMC-7 font. The fonts consist of the numbers zero through nine and four characters that send messages to the computer about what to do with the information. These 14 characters are the only ones in the true fonts, but some people have developed full fonts in the style of the magnetic ink characters for use on personal computers.
The most common use for magnetic ink character recognition is in banking. Checks often bear magnetic markers of the account number and routing number of the account from which they draw. These magnetic characters are used to sort checks. Automating this part of banking allows bankers to process checks more quickly.
Magnetic ink character recognition is widely used because of its many benefits. The computer reader relies on the placement of the magnetic powder rather than the appearance of the ink, so crossing out the numbers or writing over them does not decrease the accuracy of the readings. Checks that are sorted using this method are rarely misdirected, and because of this the method has survived since its development in the 1950s.