Image Number 5 for United States Patent #7143950.
The present invention provides ink that is designed to cohesively fail upon a de-lamination attack. A resulting failure pattern is preferably difficult to predict. The ink is applied to an identification document including a core and laminate layer. The ink is characterized such that an adhesive strength of the ink to the core and an adhesive strength of the ink to the laminate layer is each greater than the cohesive strength of the ink itself. Thus, the ink rips apart in a somewhat random-like manner upon a de-lamination attack. The ink can be arranged in interwoven or interlocking patterns or in other desired patterns and locations.