I use screen wipes,that you clean a PC's screen with,they do a good enough job.
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i just use a bit of windex on a towl.
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Regular household polish does the job too.
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i used the steam from my breath, and i use a cloth to wipe it, (i got the cloth with a laser pen for cleaning it) or sometimes i'll use a cloth i got included with my TV or Monitor. (lcd one) also, when i tried typing this on my phone, i went to go into the options button to press "Done" and it only said edit, so i pressed down, and it refreshed my page :o, it done this 4 times! :(
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I wear glasses, so I always carry a lens cloth in my pocket, perfect for cleaning the screen and good for those oily finger marks that can be resistant to other materials.
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I sell...and therefore always have at hand...a microfibe cloth Great for screens etc
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"Flatpanel" Plasma/LCD/TFT Gel Screen Cleaner (anti-run, anti-static) - wiped off with a lens-cloth... Does an amazing job, ideal for cleaning all dust & smudges from the screen before applying a protector... Works well on PC monitor screens too... This was from Richer Sounds in the UK but no doubt there are many similar products available.
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I have a screen cleaner, but its really dodgey, it came with the screen protector i threw away (Explains it i guess :P). Ill get one from a store selling glasses or something. Thanks
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with screen protector on i just use my shirt. :)