| abstract |
A method and compositions for authenticating a document or article comprises applying a mixture of a carrier, a leuco dye and an activator to a surface of a document or article, wherein the leuco dye and activator react in response to a rubbing force applied to the surface to change color and wherein the activator is at least one selected from the group consisting of amidophenol, anilides with hydroxyl groups and benzoamides with hydroxyl groups and authenticating the document or article by applying a rubbing force to the surface to effect a color change. |