To paint a large section without leaving lap marks, roll the nearly dry roller in different directions along the dry edge, feathering out the paint as you go. After completing the entire length of the wall or ceiling, move to the next section and paint over the feathered edges. For the second coat, apply the paint in the opposite direction. This crisscrossing paint application sharply reduces (if not eliminates) lap marks.
"Cutting in is an acquired skill, but it's something you can't do at all with a ratty brush," says Doherty. When cutting in on a wall, he loads his brush and spreads out the excess paint, then works the brush up to the line between wall and ceiling. A brush stroke that's too wide creates a hatband, or smooth brushed band, on the very top of the wall where it meets the ceiling. To avoid this, Dixon recommends rolling first and then cutting in with a brush. "A good roller can get within 1/2 inch of the ceiling," he says. "You'll save time by not brushing more then you have to." When painting baseboards, "a wide taping knife makes a good paint guard," says Span. "Just keep the blade clean to prevent drips from working around the edge of the knife."
This was very helpful. I wonder if i would really follow through and check to see if my painter was cheating me. I used a painter I found on Angie's List. This was 5 years ago. He did a great job. I know he did patching only for about a day and a half. We decided on the kind of paint before he started. that is what he used. I don't know if I could stay on top of him and watch him open every can of paint.