My responsibility in the Kurz Group is a special product group, which
we call hotstamping foils with optical variable effects. In this
collection you will find Holograms, Kinegrams and Diffraction Foils,
but also some products with additional printed effects.
Werner Reinhart, Werner Reinhart,
"Hot stamping foil: vehicle for OVD concepts on optimized processing", Proc. SPIE 1210, Optical Security and Anticounterfeiting Systems, (1 April 1990); doi: 10.1117/12.17923; https://doi.org/10.1117/12.17923