OPTICALLY VARIABLE INK WITH POLARIZING EFFECT STEP

An optically variable iridescent ink which changes its colour at different angles of illumination and observation. It contains liquid crystal pigments with periodic spiral molecular structure. Ink colour depends on the lead of the spiral and angle of illumination. Colour changing effect is achieved due to interference. Incident light reflected from the ink interacts with the spiral of a liquid crystal molecule and becomes polarized.

a                                                       b

a - general view, STEP element location; 

b - observation of optically variable ink properties: colour changing effect at different angles of illumination and observation; c - STEP element at a right angle of observation and illumination; d — the same image at an acute angle of observation and illumination; e - ink structure: iridescent and liquid crystal pigments; f - view through a polarizing filter (dark area on the right) proves that the reflected light is polarized