Admixing a pigment and dye to a binder, the dye to indicate attempted chemical or mechanical alteration to a document

摘要

Disclosed is a toner (102) for printing documents that are difficult to chemically or physically forge and that are readily easy to visually verify. The toner (102) includes a colorant, a fluorescent pigment and a migration enhancing agent. The colorant is used for printing an image on a surface of a document. Under normal lighting, the fluorescent pigment is masked by the colorant. However, when irradiated by black or ultra-violet light, the fluorescent pigment creates a visible image on the first surface (106) of a substrate (104). An image formed using the toner (102) is readily verified by comparing the colorant-formed image and the dye-formed image. In addition, if a solvent is used in an attempt to alter the printed image on the substrate (104), the dye (110) migrates or diffuses to indicate tampering with the document.