Things You'll Need
Latex paint conditioner
Streaking paint can quickly ruin many hours of hard work, leading to a frustrating painting experience. Semi-gloss, a common paint finish, makes walls somewhat shiny and reflective, making the room seem brighter. Like most paint jobs, preparation of the painting surface is key to a successful, streak-free, semi-gloss paint job on your walls.
Look for chipped or peeling paint. Remove it with a paint scraper to create an even and smooth surface for the paint.
Fill a bucket with warm water and a few drops of dish detergent. Use a lint-free cloth to wash the walls clean of dirt, oils and dust. This is one of the biggest factors in preventing semi-gloss streaking.
Prime your wall with a latex primer. This will create an even coat of color and help the paint adhere and avoiding streaking.
Add latex paint conditioner to the paint to avoid brush streaks. Occasionally the paint may be too thick, and brush streaking will occur. A latex paint conditioner will help the paint spread evenly on your walls.
Using paint rollers whenever possible eliminates brush streaking as well. Choose a roller with a thin nap for the smoothest surface.