Anti-Stokes Ink
An ink which contains crystals of rare-earth metals (ytterbium, thulium, etc.) and luminesces when exposed to high-intensity IR light 970-990 nm.
![USA. Passport issued in 2006: сover. Gold stamping. White light](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/ANTI_STOKES_INK/1l.webp)
a
![USA. Passport issued in 2006: the same. Anti-Stokes, green luminescence: text, emblem, biometric symbol](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/ANTI_STOKES_INK/2l.webp)
b
Fig. 1. USA. Passport issued in 2006:
a — сover. Gold stamping. White light; b — the same. Anti-Stokes, green luminescence: text, emblem, biometric symbol
![Russian Federation. Residence permit to a stateless person issued in 2012: front endpaper. Paper substrate. Green decorative frame, intaglio printing. White light](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/ANTI_STOKES_INK/3l.webp)
a
![Russian Federation. Residence permit to a stateless person issued in 2012: the same. Anti-Stokes, green and red luminescence of the guilloche frame](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/ANTI_STOKES_INK/4l.webp)
b
Fig. 2. Russian Federation. Residence permit to a stateless person issued in 2012:
a — front endpaper. Paper substrate. Green decorative frame, intaglio printing. White light; b — the same. Anti-Stokes, green and red luminescence of the guilloche frame
![Poland. Service passport issued in 2012: front endpaper. Paper substrate. White light](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/ANTI_STOKES_INK/5l.webp)
a
![Poland. Service passport issued in 2012: the same. Anti-Stokes, green luminescence over the whole document page](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/ANTI_STOKES_INK/6l.webp)
b
Fig. 3. Poland. Service passport issued in 2012:
a — front endpaper. Paper substrate. White light; b — the same. Anti-Stokes, green luminescence over the whole document page
![Poland. Visa issued in 2011: paper substrate](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/ANTI_STOKES_INK/7l.webp)
a
![Poland. Visa issued in 2011: the same. Anti-Stokes, green luminescence of the number](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/ANTI_STOKES_INK/8l.webp)
b
Fig. 4. Poland. Visa issued in 2011:
a — paper substrate; b — the same. Anti-Stokes, green luminescence of the number