When you’re painting with a roller, you can’t get right up to the edges were the walls meet the ceiling or the walls intersect with each other. Filling in this area is called “Cutting in.”
Use this method for painting next to the molding, trim, and baseboards as well. These are areas rollers or sprayers cannot neatly reach. With a 2 ½-inch brush, paint all these edges before doing the large surfaces. Cut in by dragging the bent bristles in a constant line, supplying paint to meet into the other surface.
You can also use a paint edger. This sponge-type brush has a small set of wheels on the side that enable it to make a close, even cut. A paint edger or straightedge can be used next to trim or baseboard to be sure that no paint gets onto the wood. Cut in around all appropriate areas before painting the large surfaces.
Our painting consultant Ed Kimble of Interior House Painting Blog says, “With flat paints, you can actually roll the wall first, and you will see a very small area left that needs to be cut in, about ½ inch. It works great. But with satin or semi-gloss (shiny) paint, the stipple of the roller really shows up, so it actually is advisable to cut in first, because the roller and brush have a different signature, and you do not want the brush strokes to show. You either have to work very fast, while the brush work is still wet, or let it dry then use the roller. Semi-gloss paint takes a long time to dry. It becomes tacky rather quickly, however, and will ‘pull’ up when you go over it with a roller, so do one wall at a time and be fast, or cut and wait.”
With the cutting in done, you can move on to the large surfaces.