you can get a gallon of flat white paint from Home Depot for $7 . I would go with bare walls before I used foil .
realy, then why is easy grow light tight made with foil. ive yet to see any damage from it....forum myths.
mylar suks. light tight isnt mylar,. its aluminum foil infused in layers into the back white panda film....watch what happens when you get mylar wet.,...you can see through it.
http://www.easy-grow.co.uk/pdf/Easy_Grow_American_Leaflet.pdf
It's possible to get hot spots with foil if the light is very large but I've never seen a 400W create any kind of hot spot with foil.
Material Percent Reflected
Foylon 94-95%
Reflective Mylar 90-95%
Flat White Paint 85-93%
Semi-gloss White 75-80%
Flat Yellow 70-80%
Aluminum Foil 70-75%
Black Less Than 10%
Got a reputable reference for all these figures ????
you did...and he said any reputable ones.