By fanning through a group of returned checks, a counterfeit may stand out as having a slightly different color than the rest of the checks in the batch.
Perforation
Most checks produced by a legitimate printer are perforated and have at least one rough edge. However, many companies are now using in-house laser printers with MICR capabilities to generate their own checks from blank stock. These checks may have a micro-perforated edge that is difficult to detect.
MICR Line Ink
Most, but not all, forgers lack the ability to encode with magnetic ink the bank and customer account information on the bottom of a check. They will often substitute regular toner or ink for magnetic ink, which is dull and non-reflective. Real magnetic ink applied by laser printers is the exception and may have a shine or glosss.
Routing Numbers
The 9-digit number between the colon brackets on the bottom of a check is the routing number of the bank on which the check is drawn. The first 2 digits indicate in which of the 12 Federal Reserve Districts the bank is located. It is important that these digits be compared to the location of the bank because a forger will sometimes change the routing number on the check to an incorrect Federal Reserve Bank to buy more time.
