Short wavelengths of radiation beyond the visible range, in the 400 to 10 nanometre range. UV radiation in the 350 to 400 nm range is used to cure printing inks. See UV curing.
Inks that are liquid until exposed to strong ultra-violet light, at which point they solidify almost immediately by polymerisation.
The polymerisation process by which a UV-curable ink almost instantly changes from a liquid to a solid when exposed to UV light. The liquid ink contains long-chain molecules called monomers that can move freely. Exposure to UV light causes them to become entangled so they cannot move and so they become a solid.