technically, Mylar reflects more light than flat-white paint ... something like 95%, compared to 88%, for whatever those figures are worth ... regardless, I recently discovered my two-year old expensive Mylar reflects very little, much less than the white paint ... seems the Mylar dulls over time, especially if you try to keep it clean (windex, etc) ... my next cabinet will definitely be flat-white paint, its so easy to just throw on another coat between crops, while the Mylar looks more and more dull, every day ... save your money, PAINT ... :thumbsup: