Interlocking document security features using incompatible inks

Abstract

A security feature for an identification document comprises a base document layer, including a first image printed with a covert ink, and a personalized image relating to a bearer of the document (such as a facial photo) printed over the first image. The personalized image is printed with an ink that is incompatible with the covert ink such that the first image becomes overt within the personalized image upon printing of the personalized image. This feature creates an interlocking relationship between the covert image, which may be pre-printed prior to personalization on card stock, and personalized information printed over the covert image. Variations of this feature can be made in which the first image is not covert, yet still creates an interlocking relationship due to ink incompatibilities. Further, the second image may depict information other than personal information.

Dependencies are inferred from the claim text.