US Patent 7670659 Substrate marking using encapsulated materials

Substrates, coatings and methods for marking substrates using the coatings. The substrate contains a coating of encapsulated marking materials. Capsules of the encapsulated marking materials are designed to preferentially absorb a predetermined wavelength of light or range of wavelengths of light. The capsules contain color chemistry capable of activation by the predetermined wavelength of light or range of wavelengths of light for the generation of a color response. By utilizing capsules of differing color chemistries, such substrates are capable of multi-color image generation.