Ink is exposed to UV radiation where a chemical reaction takes place where the photo-initiators cause the ink components to cross-link into a solid.
Typically a shuttered mercury-vapor lamp is on either side of the print[print?:printing image graphic cutting solution] head, and produces a great amount of heat to complete the curing process (this lamp is used for free radical UV ink, which is what the majority of flatbed inkjet systems use).
UV inks do not evaporate, but rather cure or set as a result from this chemical reaction.
No material is evaporated or removed, which means about 100% of the delivered volume is used to provide coloration.
This reaction happens very quickly, which leads to instant drying that results in a completely cured graphic in a matter of seconds. This also allows for a very fast print process.
As a result of this instant chemical reaction no solvents penetrate the substrate once it comes off the printer, which allows for high quality prints.
