US Patent 8025952 Printed magnetic ink overt security image

A security image and method of forming said image is disclosed wherein a substrate having an image or indicia thereon is coated with a dilute solution of pigment flakes in an ink or paint. The flakes are subsequently aligned in a magnetic field and are fixed after the field is applied. Most or all of the flakes in a region are aligned so as to be partially upstanding wherein their faces are essentially parallel. Coating the image with flakes yields a latent image which can be clearly seen at a small range of predetermined angles.