Quote Originally Posted by John Koehrer
If you acquire these lamps DO NOT handle the bulb itself.
They're called quartz halogen because the envelope containing the filament is quartz, the gas inside the envelope is halogen.
If you handle the envelope, it will absorb oils from your skin and drastically shorten the life of the lamp. With the search you have made I don't think you want to do that.
Prper handling would be to handle the lamp by the edges of the reflector, not touching the envelope at all. If for some reason you need to handle the envelope cover it with a tissue or kleenex.
Thanks for the advice. Okay, when I get one (and the enlarger), I'll be very careful to handle it.