Optically variable element with a polychrome effect AURORA
An optically variable security element with a multiple colour switching effect. It was developed by Innovia Security company as a further development of the G-Switch® element. It is applied during the formation of the Guardian substrate on one of its inner layers in the form of an image (picture or alphanumeric characters). A pair of image elements that work in combination appear as one colour at certain observation conditions, then a totally different colour at other observation conditions. Ink pigments which are semi-transparent in transmitted light have a pearlescent sheen in reflected light. The effect of a colour switch is observed both on front and reverse side of the banknote if the element is located on a clear window.
Scheme of observation and illumination:
a pair of images С and С' are of the same colour at an illumination angle of 0±10 degrees and observation angle of 45 degrees to the perpendicular; the colours of the images are different at an illumination angle of 0±10 degrees and observation angle of 0±10 degrees to the perpendicular
a
b
c
d
e
f
g
h
1000 Mauritanian Ouguiya (2014). Guardian polymer substrate:
a — front side, Aurora element location; b — Aurora element viewed in transmitted light; c — the same image viewed in reflected light at an angle of 45 degrees. The pair of image elements (left and right) have a similar colour; d — the same image viewed at an angle of 0 degrees: the left element is golden and the right element is blue; e, f — the same image viewed in transmitted light; g — ink pigments viewed in reflected light; h — the same image viewed in transmitted light