Visible or invisible inks containing pigments or dyes that appear when excited by exposure to a specific wavelength of light (like UV or IR) which then re-emit a new wavelength, usually in the visible range. Some UV inks are tailored to respond at specific wavelengths. UVA = 365nm (long wave) UVB = 315nm (medium wave)…
Materials that emit light following the absorption of light or other types of radiation. A form of photoluminescence, fluorescent materials in most cases emit light with a longer wavelength, and therefore lower energy, than the absorbed radiation. The most common example being with UV materials, executed at 365nm (for example) and emitting at 440nm.
Materials that provide a measurable response to Infrared (IR) energy. Responses can be visible, invisible or can cause an image or text to “drop out” of the visible spectrum when exposed to IR light.
“Taggants” is a category name for materials that do not occur naturally in the tagged substrate, ink, or other carrier. Rare Earth taggants can be detected using IR wavelengths that cause an anti-stokes reaction that is not common in nature, which results in the emission of a higher energy (in the visible spectrum) than the…
