Things You'll Need
Blue edging tape
Semi-gloss paint is different than a matte paint in that semi-gloss paint tends to go on runnier. It can seem streaky to a beginner. But that streakiness is part and parcel with what makes semi-gloss paint shine and make your walls look brighter. Additionally, semi-gloss paint is more likely to reflect its own color out onto the room in which it is applied. To apply semi-gloss paint to walls, you will need to prime the walls and do two or three coats of paint to make sure coverage is achieved.
Wash the walls with soft cotton cloth dowsed in warm water with some gentle soap, such as dish soap. You do not necessarily need to scrape off the old layer of paint unless it is flaking or full of cracks.
Tape off any edges over which you do not want to prime or paint. Take your time with this step, as it will make all the difference in achieving sharp lines.
Prime the wall with one or two coats of primer. For very vibrant colors you will need two coats. To apply a basic white primer, use a roller to apply the primer evenly across the entire wall. To reach into corners, use a brush.
Prepare the paint. Make sure the bucket has been shaken at the store where you buy it. When you open the bucket, stir it well, all the way to the bottom.
Pour some paint into a mixing pan. Do not fill the pan. Leave some room to roll excess paint off the paint roller when you go to dip it into the paint in the reservoir.
Dowse the roller in paint in the mixing pan. Roll off any excess in the flat part of the pan. Do not roll too much off--just enough to make sure no paint drips off the roller on its way to the wall.
Coat the entire primed and dried wall with a coat of paint. Spread as evenly as possible while refraining from spreading the paint too thin. Wait until dry. Add another coat.
If necessary, add a third or even a fourth coat.