Deliberate Error

An intentional printing mistake known only to the manufacturer and inspection officials. Typically, seen as a single event in a repeating sequence, in an attempt to trip-up criminals who try to recreate the image.

Duplex Patterns

A design made up of an interlocking pattern or irregular shapes, printed on opposite sides of the substrate. The images when viewed with transmitted light, creates one complete and registered image.


The process of creating a raised image into the substrates surface, using either a set of male/female dies or engraved plates/cylinders and magnetic flexible dies under high pressure. Tactile elements can also be created using specialty inks and/or thick layers of inks to create a raised image.

Latent Image

An image or pattern created with raised lines placed at a right angle (90 degrees) from the background, so that when viewed at an oblique angle the image is visible through light and shadow effects.

Line Screen Modulation

A method of digitizing halftone images, creating irregular spacing between lines or dots. When scanned or copied using normal frequencies the scanned image reveals a moiré pattern. Can be used in combination with a lens or filter to reveal a hidden image.