Semi-gloss paint carries a shine often desirable in kitchens and bathrooms, but not so anywhere else. It can be easier to clean than matte paint, but also shows surface imperfections more easily. If you painted a room with semi-gloss latex paint, but now don't like the shine, remove the gloss without repainting. All you need is some sandpaper to remove the shine from your walls, leaving a matte finish.
Put on a dust mask to protect your lungs.
Open the windows in the room to maximize ventilation. Turn on a fan if one is available.
Insert a sheet of 220-grit sandpaper into a sanding block.
Sand the wall, working in circular movements until the shine is gone.
Wrap sandpaper around a craft stick to get into hard-to-reach areas.
Wipe the wall with tack cloth to remove sanding dust. Sand the wall a second time, if needed.