a lot of the processes that aren't silver gelatin based ... ( pt/pd, carbon, salt, pop, albumen &C )
but ... i even have trouble exposing dense tmx with a 300w floodlight
onto plain old rc paper. tmy exposures were about 2 seconds and
tmx exposures were about 50 seconds, so it isn't just uv processes
the anti-uv layer has its fun with.