the very small scale structure of a prepared surface of a material as revealed by a microscope above 25× magnification. Diffractive microstructures comprise micro-protrusions or microgrooves or a combination thereof that are capable of diffracting light waves.


text created within a holographic image that is so small that it cannot be reproduced by photocopying or scanning, and can only be read under magnification.


a type of holographic image in which different, usually unrelated images, appear at different viewing angles.


the coating of films or surfaces with a very thin layer of metal using a metal deposition technique (generally vacuum deposition). Metallisation is what gives holograms their silver or similar metallic appearance.


a unit of measurement referring to the thickness or gauge of physical substrates and features. One micron is equal to one millionth (10-6) of a metre.