what are the ingredients that are makes UV (Ultra Violet) BlackLight (i.e Long wave...?!
that are only (Visable) under UV lights
The ingredients used in fluorescent watermark prints contains fluorescent materials
I.e. compounds absorbing photons of high energy (invisible UV-light) and thereafter emitting lower energy photons (visible light).
Also have a look at:
In money notes there are specific compounds that have specific lifetimes of the fluorescence, in addition to the wavelengths that they floresce on. So - if the notes are read with both spectrometer and fluorescence lifetime reader, fake notes should be quite easy to find.
I think rare-earth materials are used in money notes.