When I got my iMac, I noticed a speck of something on the inside of the glass. Knowing that it only took a small suction cup to remove the glass, I did, and then the troubles began. I was able to clean the spot with a "streak free" cleaner made for computer glass....it did just the opposite with the small chamois wiper...streaks everywhere! Long story short... the cleaner is great. Use NEWSPAPER to wipe it off, no streaks. The iMac is as clean as when I took it out of the box!