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