The science of hiding Image(s) or information within other image(s) or information. In security documents, the hidden image or information is typically revealed with the aid of a decoder lens, scanning device, or decoding software in a handheld or desktop device.
An image that has been embossed, debossed, or stamped into a surface of a substrate but has not been printed or foil stamped. Creates a raised impression used as an authenticator.
These inks contain microscopic pieces of metallic substances or variable pigments which display color changes depending on the angle of observation or lighting. An unaided eye will observe this effect as a change of color when the viewing angle is changed. Color shifting inks consist of multi-layered micro flakes in a transparent ink medium. The…
This is a means of applying a thick and highly pigmented ink onto paper using etched or engraved plates and high pressure. The pressure forces the substrate into the recessed areas of the printing plate, thereby producing a raised tactile relief which can be recognized under oblique light. Intaglio provides highly secure printing techniques that…
These are specialized inks that can absorb or reflect infrared light, often used to hide a message, symbol or graphic, such as a bar code, within a document. The desired message is printed with infrared absorbent ink while a black box covering the message is overprinted in infrared reflective ink, effectively hiding the message from…
These are security inks that contain a component that absorbs energy from a low energy light source such as an infrared light with a wavelength around 900 nm and emits a fluorescent reaction in the visible region or IR region but at a shorter wavelength (higher energy). Special equipment is needed to see the effect.
Iridescent or pearlescent inks contain transparent pigments consisting of a thin film deposited on tiny mica flakes. They cause interference with the incident light. This creates shiny, pearl-like shimmering effects with changes in color when the angle of view or illumination changes.
This is a specialized ink containing particles of a magnetic substance that can be read with a magnetic reader. This ink is commonly used for serialization and numbering purposes in the banking industry as well as an additional security pattern. The most common application is on the bottom portion of checks to facilitate processing and…
These inks often contain metallic pigments containing particles that mimic metals like aluminum or bronze. They are used as components of printing inks to simulate metallic or other highly reflective surfaces. Metallic ink is not a security ink in the strict sense, as it is freely available to any commercial printer; however, metallic ink is…
These are chemically different inks that are paired to appear identical under one lighting condition, but look markedly different under another lighting condition or when viewed through a filter, usually red. They are often used to embed a hidden design or shape behind another printed image. Metameric effects cannot be copied by four-color reproduction systems…
