For one thing, it seems that >these Mineral Lites are of short wavelength and won't pass easily through the >wall of the neon tubing. >Jeff Golin > > Jeff, I don't know if you work in all soda, but the uv light will amost always be blocked by leaded glass. I Have never seen a color checker that will light up a tube other that on the end. The story is different of course if you are working in say, soda or pyrex. matt