What do folks recommend. I have tried old fashioned standard bulb size blacklight bulbs, squigley shape newer style blacklight bulbs, I had longer tube style plug in blacklight at one point, and the handheld tube style. I also tried a couple very cheap but older flashlights supposedly blacklights that basically were not. From the things I have tried the only one I have relied on is the tube handheld battery ones because of ease of use. I think I still have both kinds of screw in standard sized black light bulbs somewhere. The handheld one works for me, but if there is something folks like better I want to try it. The standard sized bulbs required a lamp of some sort which then was sort of a pain to move around and store. I haven't tried any kind of UV led light at all for the purpose of exposing UV reactive glass. I love led lights for other uses however. Stick with what works or is there a more powerful focussed beam solution out there that is user friendly? LOVE LOVE LOVE my cheap led loupe. Everybody must get one!