How to Get Clean Lines When Painting Walls

Wipe off all trim edges with a damp sponge. This removes any dirt, dust or residue on the walls that may interfere with the adhesion of the masking tape.

Mask off the trim areas with painter's tape. Apply the tape slowly and carefully, pressing the tape firmly as you move along the wall. When you mask off a trim line, the majority of the tape should be on the wall or ceiling surface that is not going to be painted. One edge of the tape should just meet the edge of the wall that you are presently working on, and the remainder overlaps the unpainted wall.

Roll the paint onto the wall with a roller stopping about 2 inches away from the painter's tape. Cover the entire length and width of the wall with rolled paint, leaving the 2-inch space along the entire tape line.

Fill in the 2-inch border between the rolled paint and the painter's tape with a paint brush. This is called "cutting in." Use an angle brush to get in the corners. Load the brush with plenty of paint to avoid brush strokes.

Allow the paint to dry overnight before removing the tape. Pull the tape off slowly, at a 90-degree angle, to prevent pulling the paint up with the tape. You may want to use a razor to cut a sharp line precisely between the trim line and the edge of the tape to ensure that no paint is pulled up when you release the tape. Working in short sections also keeps the paint from lifting with the tape.