| abstract |
A document capable of providing multiple colors under the application of heat comprising a support having at least one surface bearing a first coating comprising a substantially colorless, heat activatable chromogenic composition capable of producing a first color under the application of heat, and a second coating comprising a localized coating of a substantially colorless, heat activatable chromogenic composition capable of producing a second color under the application of heat. Each chromogenic composition comprises a chromogenic compound and a color developer that are substantially colorless solids in physical contact prior to reaction, but which can chemically react to produce a visible colored image by application of heat at temperatures above room temperature. Under the application of heat from a thermal printer, by quickly striking the chromogenic composition with a fingernail or blunt object to produce frictional heat, or other heat application, multicolored images are provided. |