Ink with cohesive failure and identification document including same

摘要

The present invention provides identification documents with security features. For example, a document may include two or more inks that are designed to cohesively fail upon a de-lamination attack. A resulting failure pattern is preferably difficult to predict. The two or more inks are applied to an identification document including a core and laminate layer. At least one of the inks 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.