Similar to fibers, planchettes are added directly to paper. Planchettes are normally produced in a geometric shape, and can be a carrier for such things as Taggants. Planchettes can also be simulated by printing directly on the substrate.
A thin ribbon that is threaded or woven through paper. The public is likely most familiar with the use of threads in currency. Threads may also be taggant carriers and fluoresce when excited.
A watermark is a recognizable image or pattern in paper or plastic cards that appears as various shades of lightness/darkness when viewed by transmitted light (or when viewed by reflected light, atop a dark background), created by thickness and density variations in the paper or plastic cards. There are two main types of watermark, the…
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.
An image visible under normal lighting conditions, but disappears under an alternate light source.
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.
Two colors appear similar under normal lighting conditions, but because of differences in spectral/chemical composition, will appear dramatically different when viewed with a filter or differing light sources.
An extremely small line of text characters, symbols or images, indiscernible to the naked eye, printed at high resolution beyond the capabilities of desktop printers or scanners. This feature is often hidden in background design of vital records or as a signature line on checks and may contain intentional mistakes.
The unwanted interference pattern created when overlapping halftone dots or lines at irregular screen angles. This pattern is also used as an authenticator when intentionally printed.
A printing technique in which two colors are blended together to create a continuous and gradual transition from the first color to the second or more.
