Patent ID: 9464385
Filing Date: 2016-10-11
CPC Classification: B42D,D21H,Y10T

Claim Text:
1. A security paper comprising at least first and second fibrous paper plies, wherein the first ply is a first material layer having a first fibrous structure comprising first fibers made of a first material, and the second ply is a second material layer having a second fibrous structure comprising second fibers made of a second material, the first ply being an external ply that includes a first authentication element provided within a region of non-zero thickness of the first ply, said first authentication element comprising at least one of (i) first authentication particles made of a third material, and (ii) first authentication fibers made of a fourth material different from the first material of the first fibers of the first fibrous structure of the first ply, and the second ply comprising a second authentication element provided within an area of non-zero thickness of the second ply, said second authentication element comprising at least one of (i) second authentication particles made of a fifth material, and (ii) second authentication fibers made of a sixth material different from the second material of the second fibers of the second fibrous structure of the second ply, wherein each of the third, fourth, fifth and sixth materials of the first and second authentication elements is selected from the group consisting of iridescent particles, luminescent fibers, luminescent particles, fluorescent fibers, fluorescent particles, phosphorescent fibers, phosphorescent particles, colored fibers, colored planchettes, thermochromic fibers, thermochromic particles, fibers that react to electromagnetic fields, and particles that react to electromagnetic fields, wherein the third material of the first authentication element is different from the fifth material of the second authentication element, and the fourth material of the first authentication element is different from the sixth material of the second authentication element, and wherein (1) the first ply does not include any authentication element made of any of the fifth and sixth materials, and (2) the second ply does not include any authentication element made of any of the third and fourth materials.