?uv Light?

What is a good way to check for tagging on US stamps? Long wave or short wave uv light? And is there a certain watt that is reccomended?

You need a shortwave UV light for US stamps as I remember it. I use a small battery operated hand held one. Of course for my Canadian stuff, I also have a longwave lamp.

Yes, that is correct, you will need shortwavelength UV (something <300nm) to see tagging on most US stamps.

Mine is filtered at ~254nm (short) and ~365nm (long). The tagging will not show up at 365nm.

My lamp outputs at 6 watts, but that's overkill. I can light up a full pane of stamps without turning off the lights. For most philatelic purposes, a couple of watts should be more than sufficient -- but you may have to hold the UV lamp pretty close (1-2 inches) to the stamp.

Remember, shortwavelength UV can damage cells. While it is not necessary to wear protective eyegear or gloves when using those small philatelic UV lamps, I would avoid looking directly at the lamp bulb.

Hi to all
Khj is correct, Ultraviolet light is very dangerous, you should never ever be exposed to it for more than a maximun of three minutes at a time. As a Gemmologist we were always taught not to use the light for long periods and to wear protective eye wear.
Yet you see lots of Dance venues with "Blue Lights" I wonder how long before people realise the danger and start suing dance venues if and when they may have health problems re the lights.
Regards
Horamakhet