The optically variable coatings can prevent counterfeiting of value documents. The cost of these coatings deposited by physical technology is very high. The sol-gel technology has the feature of a relatively lower cost and can be used to produce thin films with low refractive. We studied the optically variable coatings by the nano-composite technology (i.e., compound method of sol-gel technology and physical technology). The degree of color shift of some film structures with the viewing angle, including PET (substrate)/Cr/SiO₂/Al and PET(sub.)/Cr/resin/Al etc., was calculated according to the color perception of human eyes. And the coatings produced were measured with the spectrometer.

Date Published: 29 November 2000
PDF: 4 pages
Proc. SPIE 4086, Fourth International Conference on Thin Film Physics and Applications, (29 November 2000); doi: 10.1117/12.408394

Published in SPIE Proceedings Vol. 4086:
Fourth International Conference on Thin Film Physics and Applications
Junhao Chu; Pulin Liu; Yong Chang, Editor(s)