Hello! Aluminum foil isn't too great as a reflector because it scatters light. Actually I've read that pure white is the best reflector, so painting whatever you're making your reflector out of with white paint is the best thing to do.

Hmm, good point Calvin.

Now I think of it, white is what's inside the store-bought HID reflectors I am using, and also the one bank of 40W tubes I have (not using right now).

Also, the light book I planned my light set-up from urges painting walls flat white (rather than enamel) to get maximum reflection.

I was contemplating white painted alumnium soffits at the hardware store, but they at 8 feet long by oh 18 inches wide, I could not take them with me easily. But I'm still pondering them. They're light. I'd have to cut them in two then rig something above the lamp.