... Well, as close as one can get to non-glare, anyway!
(Yes, unfortunately I have to spend a lot of time using Windows... but now at least I don't have to stare at my computer THROUGH a pane of window glass anymore!)
What I did
I removed the front glass cover using suction cups -- the screen is still glossy, but it has significantly less reflection without the glass cover.
Then I cut a piece of black mat board and affixed it around the screen.
I'm really happy with the results! I have been using the screen without the glass for a few days and love it, and it looks even better with the black border back. (You can see the info leading up to this hack here -- https://forums.macrumors.com/threads/868755/ )
Full disclosure
Don't get me wrong - it is not a matte LCD with a diffuser panel, but it is a huge improvement over that low quality glass! If you are having trouble from a specific light source behind your computer, this may or may not help you much. My reflections were not from light sources in the room, but just from my shirt/face/etc. in front of the glass.
Making the border
I work in an office with a large cutting table and all the necessary stuff (huge rulers, x-acto knives, etc.), so I just did it myself. But if you want to try this yourself, I would have your local hobby lobby or craft store do it for you. Just measure the area you want covered and they can do it for a few bucks. If I were you, I'd do a 1" border top, left, and right and a .9" border on the bottom.
Affixing the border
The original glass just has some thin metal applied behind the black border, and there are permanently attached magnets on the edge of the iMac that hold on to the metal. Since the mat board does not have anything magnetic, I used a small bit of adhesive magnetic tape to hold on the mat board. I just cut little 1/3" strips of the magnetic material, remove the backing so the adhesive was uncovered, and put one piece on each magnet around the screen with the adhesive side pointing towards me. Then I carefully laid the black mat board on the screen and used pressure to make the mat board touch the adhesive on the magnets already on the computer.
Obviously time will tell if this is a good way to adhere it.
Caveats
This worked perfectly for my needs -- I'm the only one using this computer, so it won't matter that it isn't a very well secured solution. I don't see the computer from the back, so it doesn't matter that I didn't round the top edges of the screen. Also, I am the only one who will be cleaning this screen, so I won't ever get any spray on the paper mat board (and since it is magnetic, I can remove it when I need to clean).
Do this at your own risk
Obviously, you could break about 100 things in the process of doing this... you cut your jugular removing the huge panel of NON SAFETY GLASS or your could slice off your finger trying to cut the mat board yourself. You could even knock the computer over trying to put the mat board on. Don't do it if you aren't willing to accept the risk - I'm definitely not recommending anyone do this at all, much less the way I did. I'm just sharing my personal success. So don't call me when you're bleeding on your new, broken iMac.
Like I said, I'm really happy with the results. Mainly because it is awesome to be able to use my iMac without a headache! Since I cut mine myself, it is not 100% perfect -- but I think if you had a framing shop or craft store do yours, it would look great. I wouldn't recommend that 45-degree edge they sometimes do, but maybe it wouldn't look too bad.
-Stephen
(Yes, unfortunately I have to spend a lot of time using Windows... but now at least I don't have to stare at my computer THROUGH a pane of window glass anymore!)
What I did
I removed the front glass cover using suction cups -- the screen is still glossy, but it has significantly less reflection without the glass cover.
Then I cut a piece of black mat board and affixed it around the screen.
I'm really happy with the results! I have been using the screen without the glass for a few days and love it, and it looks even better with the black border back. (You can see the info leading up to this hack here -- https://forums.macrumors.com/threads/868755/ )
Full disclosure
Don't get me wrong - it is not a matte LCD with a diffuser panel, but it is a huge improvement over that low quality glass! If you are having trouble from a specific light source behind your computer, this may or may not help you much. My reflections were not from light sources in the room, but just from my shirt/face/etc. in front of the glass.
Making the border
I work in an office with a large cutting table and all the necessary stuff (huge rulers, x-acto knives, etc.), so I just did it myself. But if you want to try this yourself, I would have your local hobby lobby or craft store do it for you. Just measure the area you want covered and they can do it for a few bucks. If I were you, I'd do a 1" border top, left, and right and a .9" border on the bottom.
Affixing the border
The original glass just has some thin metal applied behind the black border, and there are permanently attached magnets on the edge of the iMac that hold on to the metal. Since the mat board does not have anything magnetic, I used a small bit of adhesive magnetic tape to hold on the mat board. I just cut little 1/3" strips of the magnetic material, remove the backing so the adhesive was uncovered, and put one piece on each magnet around the screen with the adhesive side pointing towards me. Then I carefully laid the black mat board on the screen and used pressure to make the mat board touch the adhesive on the magnets already on the computer.
Obviously time will tell if this is a good way to adhere it.
Caveats
This worked perfectly for my needs -- I'm the only one using this computer, so it won't matter that it isn't a very well secured solution. I don't see the computer from the back, so it doesn't matter that I didn't round the top edges of the screen. Also, I am the only one who will be cleaning this screen, so I won't ever get any spray on the paper mat board (and since it is magnetic, I can remove it when I need to clean).
Do this at your own risk
Obviously, you could break about 100 things in the process of doing this... you cut your jugular removing the huge panel of NON SAFETY GLASS or your could slice off your finger trying to cut the mat board yourself. You could even knock the computer over trying to put the mat board on. Don't do it if you aren't willing to accept the risk - I'm definitely not recommending anyone do this at all, much less the way I did. I'm just sharing my personal success. So don't call me when you're bleeding on your new, broken iMac.
Like I said, I'm really happy with the results. Mainly because it is awesome to be able to use my iMac without a headache! Since I cut mine myself, it is not 100% perfect -- but I think if you had a framing shop or craft store do yours, it would look great. I wouldn't recommend that 45-degree edge they sometimes do, but maybe it wouldn't look too bad.
-Stephen