Anti-Stokes Ink
An ink, containing crystals of rare-earth metals, which glows when exposed to IR light of high intensity. When viewed in such spectrum, the surface of the image looks like a brightly glowing printed area or dots (fig. 1).
Fig. 1. Anti-Stokes fluorescence. 5 000 Russian Rubles (1997).
Images of anti-Stokes fluorescence of banknotes are available in the Forensic version of the Database