A security ink containing dyes designed to penetrate the substrate (usually paper) so that any attempt at mechanical erasure will cause visible damage to the document. These inks are very difficult to remove from a document without causing damage. They are commonly used to prevent forgers from manipulating data on a document. The inks are…
These inks contain a security agent that is sensitive to chemicals commonly used to alter documents, e.g., polar and non-polar solvents and bleach. Any attempted chemical attack will cause sensitized surfaces to run, bleed, stain, reveal hidden text, change color or even disappear, indicating tampering.
This ink produces a transparent or white image on a substrate. Rubbing the printed area with the edge of a coin or metal object can reveal the image. Coin reactive ink cannot be copied and provides immediate verification of a document’s authenticity without the use of any specialized devices. Effect from rubbing the printed area…
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…
Erasable inks are generally used in the printing of background artwork. When an attempt is made to mechanically alter or erase information, the artwork is removed in that area. Erasable inks are designed to react in the same manner as solvent or chemical reactive inks. Scenic or pantograph backgrounds on checks are commonly printed with…
This soluble ink is used to protect against alterations. When exposed to water or chemical solvents, the security printing will disappear or otherwise distort.
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.
