Security Foils

[aqazi81]

Anybody knows how these are made?

 

[chevalier]

It's basically the same technique as cast and cure UV coating. Micro (nano?) etching of a film, coating or foil creates light refraction and/or diffusion. There's an entire KURZ foil set called Light Line of standard ones but they can also be custom manufactured. Some country's currency uses this technique for anti-counterfeiting. Canada and Austrailia comes to mind.