You can use the black/white Polly as a wall. I've seen it many times as room dividers. I guess that is what he must have been thinking. Mylar does have a transparent element to it anyway.

Way to many people freak out if there is even the sliest amount of light that gets through. It's more about the lumens and not just the white light anyway. Itâ??s not like a few seconds or even a few minuets of light will shock the plant. They are stronger then that, and a little light leak will not have as much affect on a plant as most people think. Itâ??s not like a little leak will have enough lumens to affect much if anything of the plant. Total dark is great but itâ??s not going to wreck the plant or even affect the final harvest if there is a little light leak.

Just to put things into a little perspective for you dude.