Cutting in
Also called: cut in, cutting-in, edging, brushing the edges, cut line, freehand edge
Painting the edges a roller can't reach — the ceiling line, inside corners, around trim, outlets and windows — with a brush before rolling the field. A 2–3 inch band drawn freehand with an angled sash brush; done well it replaces tape, and it is the skill that shows in a finished room.
A roller covers the middle of a wall but stops an inch or two short of every edge: the line where the wall meets the ceiling, the corners, the trim around doors and windows, the baseboard, the outlets. Cutting in is brushing those edges first, in a band a few inches wide, so the roller can then come in and overlap the band while it’s wet. Painters cut in one wall and roll it, then move to the next, so the brushed band and the rolled field blend without a visible line.
The tool is a 2.5-inch angled sash brush, loaded a third of the way up the bristles and tapped — not wiped — on the can. The stroke: set the brush a half-inch from the edge, press until the bristles fan, and draw it along the line in one long pass, letting the fanned tip ride the edge. Then feather the inside of the band so it doesn’t dry as a ridge. A steady hand takes about a room to develop, and a wobble is fixed with the ceiling color and the same brush.
Tape is the alternative, and painters use it on baseboards and surfaces they can’t afford to touch, but rarely on the ceiling line: tape bleeds along textured drywall, takes longer to apply than a brushed line, and can pull the film when it’s removed. The DIY guide covers the order; the short version is cut, roll, next wall.