"Cutting in" along the ceiling with a brush is an essential first step when painting a wall with a roller — a roller can't paint up against adjacent surfaces. Unfortunately, telltale brush strokes often remain around the perimeter of the room once the paint dries. To hide the evidence, simply slide the sleeve off the roller cage about 1 inch so it extends past the protruding knob. You'll be able to roll very close to corners and ceilings and paint right over the cut-in brush strokes. To avoid messy fingers, slip your hand inside a plastic sandwich bag before grasping the wet sleeve.