Infra-red "Nytewriter" Marking Pens

Pattern visible through night vision device

Infra-red “Nytewriter” marking pens were developed for writing/drawing patterns (codes, words, symbols, or images) on a wide variety of substrates and surfaces. The patterns created by applying unique IR-absorptive ink formulations are readily visible when viewed under near (NIR) night visions devices (NVD) because of the high NIR-absorptivity of the compounds used in preparing the ink formulations. Conversely, the effects achieved by the IR-absorptive marker inks when viewed in normal (daylight and artificial light) light range from patterns that are readily visible on white surfaces in normal light to a transparent or “camouflaged effect” when the inks are applied to printed or colored surfaces. Hence, the IR-absorptive markers offer a wide range of detectability under normal light and night viewing conditions with NVDs. Prototype, easy to use, refillable, felt-tip, marker pens containing the IR-absorptive inks also were prepared and are being evaluated by the USMC.

The colorants used in conventional marking pens are usually visible on undyed, dyed, or printed substrates. Furthermore, conventional pen inks vary in NVD-visibility, depending on the IR absorptivity of the colorants used in the ink formulation. The “Nytewriter” is unique in that the marker inks are readily visible in NVD when applied to a wide variety of undyed, printed, and dyed substrates, except those printed with colorants that have high IR-absorptivity (e.g., some blacks). The patterns produced with the IR absorptive inks are often invisible or semi-invisible when applied to dyed or printed substrates, thus creating a marking system that is only detectable under limited conditions (NVD), which can be used to convey special patterns (codes, words, symbols, or images) for safety, security, or rescue operations.