New answers tagged finish
For the best possible results, just go buy the same paint in a less glossy firm and repaint the wall. All the other solutions will take as much time and still might not give the results you want. Save time and effort and just repaint.
Just wipe it with vinegar. There will be no more gloss. Try in an inconspicuous spot first to see if you like the result before going any further.
The 2 answers you have amount to (i) roughen it, and (ii) satin/matte varnish it. I suggest doing both. When you're applying one finish on top of another, neither of which is primer/undercoat, you need a good key -- hence roughening the surface. You don't want to create visible scratches though. At some poitn you want to leave it in a warm place for a ...
You can coat it with a satin clear finish. or even a matte finish. Both are available at most paint stores and big box stores.
Use steel wool or plastic abrasive pads on it (after it's dried.) There are also "paint flattening agents" if you are looking for a chemical/additive fix for another coat.
Top 50 recent answers are included