Tip To Light Variable Message
U.S. Patent 5,762,378
A word, such as "$AFE" is ghost engraved on a special tamper resistant material that, once signed or printed on, cannot be easily altered. If an attempt is made to remove the "$AFE" strip, the words "void" will appear in the background. This feature works especially well in the amount field when amount alteration is the concern. Verification is accomplished by tipping to light.