Magnetic Ink
Ink containing ferromagnetic components which have a specific reaction to the external magnetic field. Images, inscriptions or symbols applied in such ink can be identified by special magnetic sensors or visualized by magneto-optical converters.
a
b
Fig. 1. Sweden. Alien's passport issued in 2006:
a — front endpaper. Paper substrate; b — the same. The document number and the background image are printed in ink which contains ferromagnetic components. Visualized by the magneto-optical scanner Regula 7701M
a
b
Fig. 2. Azerbaijan. Visa issued in 2012:
a — sticker. Front side. Paper substrate; b — the same. The document number and the barcode are printed in ink which contains ferromagnetic components. Visualized by the magneto-optical scanner Regula 7701M