Abstract:
A document includes paper having an average surface roughness of at least about 0.5 microns and including one or more optical brighteners, and includes at least one image thereon wherein the at least one image includes clear binder and light absorbing material that absorbs light only at wavelengths below 350 nm. The image is substantially not detectable to a naked human eye through differential gloss or exposure to light having wavelengths of 365 nm or more, but may be revealed to the naked human eye by exposing the document to light having a wavelength at which the light absorbing material absorbs light.
Abstract:
A document includes paper having an average surface roughness of at least about 0.5 microns and including one or more optical brighteners, and include s at least one image thereon wherein the at least one image includes clear binder and light absorbing material that absorbs light only at wavelengths below 350 nm. The image is substantially not detectable to a naked human eye through differential gloss or exposure to light having wavelengths of 365 nm or more, but may be revealed to the naked human eye by exposing the document to light having a wavelength at whi ch the light absorbing material absorbs light.
Abstract:
PROBLEM TO BE SOLVED: To provide a document and a method of making document which, by embedding the classified information or the picture with an easy operation, makes it practically impossible to detect the information by the human naked eye due to the differential gloss and furthermore is unable to be detected or disclosed even with the blacklight. SOLUTION: The document includes paper base material having an average surface roughness of at least about 0.5 microns and including one or more optical brighteners. The paper base material includes at least one image thereon, wherein the at least one image includes clear binder and light absorbing material that absorbs light only at wavelengths of less than 350 nm. COPYRIGHT: (C)2009,JPO&INPIT