IR Fluorescent Inks
Inks containing fluorescent pigments which glow when exposed to visible light of 400-530 nm. Fluorescence appears in IR light of 850-950 nm as bright light images on a dark background.
![Oman. Passport issued in 2014: central page spread with a stitching thread. Paper substrate. White light](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/IR_FLUORESCENT_INKS/1l.webp)
a
![Oman. Passport issued in 2014: the same. IR fluorescent inks. A picture on the page spread, a stitching thread](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/IR_FLUORESCENT_INKS/2l.webp)
b
Fig. 1. Oman. Passport issued in 2014:
a — central page spread with a stitching thread. Paper substrate. White light; b — the same. IR fluorescent inks. A picture on the page spread, a stitching thread
![Slovenia. Diplomatic passport issued in 2009: page 17. Paper substrate. White light](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/IR_FLUORESCENT_INKS/3l.webp)
a
![Slovenia. Diplomatic passport issued in 2009: the same. IR fluorescent inks. Text, security fibers, a security thread](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/IR_FLUORESCENT_INKS/4l.webp)
b
Fig. 2. Slovenia. Diplomatic passport issued in 2009:
a — page 17. Paper substrate. White light; b — the same. IR fluorescent inks. Text, security fibers, a security thread