MICR (magnetic ink character recognition) is commonly used in the banking industry to print information on checks that can be read quickly by both machines and humans. Although the toner used in all of Apple's black and white LaserWriter printers is magnetic, the formulation is not appropriate for MICR use. Special MICR toner cartridges for some Apple LaserWriter printers can be purchased from third-party vendors such as Printerm Datascribe, Inc.
MICR fonts which are machine readable can be ordered from most of the larger font houses such as Adobe Systems.
The Tech Info Library article titled "Locating Vendor Information" can help you search for a particular vendor's address and phone number.