Patent ID: 6531032
Filing Date: 2003-03-11
Classification: D21F,D21H

Abstract:
A security paper defined by a consolidated mass of interrelated paper fibers, said security paper comprising a light-colored base paper having first and second opposing major surfaces, a non-protection area of a first thickness between the first and second major surfaces, and a protection area of a second thickness between the first and second major surfaces, wherein the first thickness is greater than the second thickness, a limited quantity of colorant being disposed on at least one of the first and second major surfaces, including in both the protection area and in the non-protection area, the colorant being substantially limited to surface areas of said security paper, such that the protection area exhibits a lighter color, relative to the non-protection area, when viewed using transmitted light, and exhibits the colorant as a darker color indication, relative to the non-protection area, when viewed using reflected light, the consolidated mass of fibers having substantially no fiber density variation between the protection area and the non-protection area.