A preferable metal foil is of {TAIL ~ aluminum} or stainless steel in a thickness of 10 to 20 μm having a total reflection rate of {HEAD ~ 80%} or more, against a tungsten lamp 
A preferable metal foil is of { TAIL ~ aluminum } or stainless steel in a thickness of 10 to 20 μm having a total reflection rate of { HEAD ~ 80 % } or more , against a tungsten lamp
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH