Blue Pill? or Red Pill?
I encountered this site on you tube, lots of great info in all his videos, and use for haunters! His wife is an artist in blacklight/paints too.
If you watch more of his videos, you will find this: I never knew this existed.real 365nm led's are expensive
there are a lot of counterfeits and most are nearer to 400nm than 365nm wavelength
real 365nm wavelength isn't visible to the eye ... if you see how "bright" the background is you'll know that it's not 365nm
now that's not to say that 395nm "black lights" don't have their place, but if you're looking for a dim background where the uv reactive paints "pop" 365nm is king
fluorescent black lights guarantee real black light, so that's my go to ... they come in various configurations, compact fluorescent & linear
they also make mercury vapor black lights, but i've never tried any, so far ;-) ... the bulbs are inexpensive, but they require an "expensive" ballast