Check Washing

Check washing is the process of erasing checks, enabling the rewriting thereof, usually for criminal purposes such as fraudulent withdrawal from the victim's bank account. Various steps can be taken by the writer of the check to reduce the possibility of falling victim to check washing. These include mailing checks by placing them in secured mailboxes, using secure ink dispensed from a gel, rollerball, or fountain pen, the filling in of all lines on the check, and careful scrutiny of bank statements.

The actual process of washing a check is relatively simple, and can be accomplished with basic solvents. Among many others, possible solvents include alcohol or nail polish remover. The actual solvent is largely irrelevant — more importantly, the polarity of the solvent is important, and must match the polarity of the dye in the ink. For example, an ink that is mostly made of a polar dye would require a polar solvent (i.e. isopropanol or acetone). Similarly, a non-polar dye would require a non-polar solvent (i.e. toluene or a similar hydrocarbon). Both nail polish remover (acetone) and isopropanol are polar molecules, and are able to pull most common inks away from paper quite easily, in a matter of minutes.