Invisible to the eye until exposed to a specific light wavelength, revealing the ink by fluorescence.

Types of inks

• Ultraviolet light
• • Single wavelength
  • Dual wavelength
• Infrared light

This kind of inks is usually intended for medium and low security documents, but they are also used as a supplement to other measures in high security documents.
Dual-wavelength fluorescent inks, as explained above, are normally used in documents requiring a higher level of protection.

Observations
A specific device is needed to verify this ink.

Security level
Medium