ALEXANDRIA, Va., June 17 -- United States Patent no. 12,311,406, issued on May 27, was assigned to SICPA HOLDING SA (Prilly, Switzerland).

"Methods for producing optical effect layers comprising magnetic or magnetizable pigment particles and exhibiting one or more indicia" was invented by Thibaut Martini (Nyon, Switzerland), Herve Pittet (Chatel-St-Denis, Switzerland), Patrick Veya (Aclens, Switzerland), Riccardo Ruggerone (Echallens, Switzerland) and Jean Garnier (Corcelles-le-Jorat, Switzerland).

According to the abstract* released by the U.S. Patent & Trademark Office: "The invention relates to the field of the protection of security documents such as for example banknotes and identity documents against counterfeit and illegal reproduc...