Rainbow Effect on Laminate
Thin-film coating in the form of a stripe, text or image with the effect of interference color change under different angles of observation and illumination. Does not contain coloring pigments. The coating looks transparent in diffused light. In direct incident light the coating looks bronze red when viewed at a right angle. In oblique light the color of the coating changes to green when viewed at an acute angle.
Fig. 1. Visualization scheme of the color changing effect. The angle of illumination is equal to the angle of observation
a
b
c
d
Fig. 2. Sweden. Service passport issued in 2001:
a — page spread (pages 2–3). Rainbow effect on laminate (marked with a frame); b — the same. Page 2. Angle of illumination — 90°, angle of observation — 90°; c — the same. Color change effect. Angle of illumination — 45°, angle of observation — 45°; d — the same. Zoomed fragment. Structure of thin-film coating