Patent ID: 8846778

Claim:
A method for making a plurality of tactile marks on a security document substrate, comprising the steps: (a) printing deposits onto the security document substrate in a predetermined pattern using an ultraviolet light curable deposit material comprising: (i) 20-80% by weight of low viscosity acrylate having a viscosity below 200 cP at 25° C.; (ii) 1-30% by weight of urethane acrylate; (iii) 1-30% by weight of reactive diluent; (iv) photoinitiator in an amount sufficient to enable curing of the deposit material; (v) 1-10% by weight of rheological adsorbing additive comprising silica; and, (vi) 2-30% by weight of trifunctional acid ester, wherein the specified weight percentages of components (i)-(iii), (v) and (vi) are relative to a total weight of components (i)-(vi) combined, and the deposit material has a viscosity in the range of about 2,000 cP to 25,000 cP at 25° C.; and, (b) exposing the printed deposits to ultraviolet light to cure the printed deposits and form a plurality of tactile marks on the security document substrate wherein the tactile marks have easy-to-feel tactility for assisting the visually impaired to distinguish the printed, exposed security document substrate.