Optical variable device

An optical variable device or optically variable device (OVD) is an

embossing

.

OVDs are based on

diffractive optical structures. This gives cards the appearance of having different patterns, colours, and designs depending on the amount of light striking the OVD and the angle the OVD is viewed at. Holograms

are a type of OVD.

References

^ "More about Optically Variable Devices (OVDs)" Product Authentication & Security Directory
^ ^a ^b Council of the European Union, General Secretariat (10 May 2020). "The Council of the European Union PRADO Glossary". PRADO Glossary. Retrieved 10 May 2020.

This optics-related article is a stub. You can help Wikipedia by expanding it.

[1] "More about Optically Variable Devices (OVDs)" Product Authentication & Security Directory

[council-2] Council of the European Union, General Secretariat (10 May 2020). "The Council of the European Union PRADO Glossary". PRADO Glossary. Retrieved 10 May 2020.