Optically Variable Magnetic Ink (SPARK, OVMI)

OVMI – Optically Variable Magnetic Ink

A multi-level (visual and machine readable) security feature. The visual effects are based on the magnetic properties of an optically variable magnetic ink. The ink contains a special magnetic pigment located with the help of magnetic fields within the ink layer. When the banknote is tilted, there is a combination of the colour changing effect and (unlike optically variable ink) the dynamic effect of the ink movement (bright parts of the image “change” places). Usually printed by screen printing (fig. 1).