Choosing edges and cutting in tools
The list above is what exists. This is how to decide which of it you actually need, what separates a tool worth keeping from one that ends up at the back of a drawer.
Cutting in is a loading and pressure problem
Load the brush about a third of the way up the bristle and tap off rather than scraping. Then set the brush 20mm short of the line, press gently so the bristles fan toward the line, and draw it along in one continuous movement.
That approach beats trying to place the tip exactly on the line, because a loaded brush pushed to a line squeezes paint over it. The paint arrives at the line rather than being dragged there, which is why the technique produces a crisp edge.
- Load a third up
- Tap off the excess, do not scrape. A scraped brush has no paint in the reservoir.
- Start short of the line
- 20mm away, then let pressure walk the bristles up to it. Do not aim the tip.
- One continuous stroke
- Stopping mid line leaves a join that shows. Work in lengths you can complete.
- Less paint near the line
- A heavy brush at the edge is what floods over it. Load away from the cut.
Why tape bleeds, and how to stop it
Paint gets under tape through the gaps left by surface texture. On a smooth gloss it seals well and on textured plaster or woodchip it barely seals at all, which is why tape works beautifully in one room and not the next.
The fix is to seal the tape edge first: burnish it down hard with a plastic tool, then run a thin coat of the existing colour along the edge. That coat seals the gaps, and any bleed is the colour that was already there.
- Burnish the edge
- Press it down hard with a plastic tool. Finger pressure alone leaves gaps.
- Seal with the old colour
- A thin coat along the tape edge first. Any bleed then matches what was there.
- Texture defeats tape
- On plaster or paper with a pattern, tape cannot seal. Cut in by hand instead.
- Remove while soft
- Or score the edge with a knife first. Dry paint peels off with the tape.
Order of work at an edge
Cut in first, then roll. Rolling toward a wet cut in blends the two, so no brush texture shows in the corner. Roll first and the cut in sits on top as a visible band a brush width wide.
The other rule is to cut in only as far ahead as stays wet. On emulsion in a warm room that is a couple of metres, so working round a whole room before rolling produces a dry edge that shows as a line.
- Cut in, then roll into it
- Rolling toward a wet cut blends them. The reverse leaves a visible band.
- Keep it wet
- Cut only as far ahead as stays wet, which is a couple of metres in a warm room.
- Roll close to the edge
- Within 30mm. Leaving a wide brushed band is what makes the corner look different.
- Ceiling before walls
- So any overspray onto the wall gets covered. Then walls, then woodwork last.
The edges that are genuinely hard
An uneven ceiling line has no straight line to follow, so you paint a straight line and let the shadow gap absorb it. A textured ceiling meeting a smooth wall is best cut just below the texture rather than trying to follow it.
Behind a radiator, into a corner and against a carpet all need a different tool rather than more care: a radiator brush, a small brush loaded lightly, and a shield or masking film respectively.
- Paint straight, not true
- On a wavy ceiling line, a straight painted line looks right. Following the wave does not.
- Cut below the texture
- Where an artex ceiling meets a wall, take the line just below the roughness.
- Corners need a small brush
- A wide brush in a corner splays and floods. Change tool rather than technique.
- Carpet needs a shield
- Tape does not stick to pile. A rigid shield tucked into the gap does.
Reaching a high edge safely
Cutting in a stairwell or a high ceiling from a ladder is where most decorating accidents happen, because the work needs both hands and a lean. A pole extension for a brush or a pad avoids the lean entirely.
Where a ladder is unavoidable, a platform or a small tower is worth hiring for a day. Overreaching sideways from a ladder is the specific movement that causes falls, and it is exactly what cutting in a long edge encourages.
- Extension pole first
- A pad or brush on a pole reaches a high edge with both feet on the floor.
- Do not reach sideways
- Move the ladder. Overreaching is the movement that causes the fall.
- Hire a platform
- For a stairwell or a tall room, a day's hire costs less than an accident.
- Both hands free
- A pot hook on the ladder, or a belt pot. Holding a tin while cutting in is the problem.
Frequently asked questions
- What is the best tool for painting edges?
- An angled sash brush, 50mm or 63mm, used well. Load a third of the way up the bristle, start 20mm short of the line and press gently so the bristles walk up to it. Tape, shields and pads all help in specific situations, and none of them beats a good brush.
- How do you cut in a straight line when painting?
- Set the brush short of the line, apply light pressure so the bristles fan toward it, then draw along in one continuous stroke. Do not try to place the tip on the line, since a loaded brush pushed against a line squeezes paint over it.
- Why does paint bleed under masking tape?
- Surface texture leaves gaps the paint runs into. The fix is to burnish the tape edge down hard with a plastic tool, then paint a thin coat of the existing colour along it first. That seals the gaps, so any bleed is the colour already there.
- Should you cut in before or after rolling?
- Cut in first, then roll toward the wet edge so the two blend. Rolling first leaves the cut in sitting on top as a visible band a brush width wide. Only cut as far ahead as stays wet, which is a couple of metres in a warm room.
- Do you need tape to paint a straight edge?
- No, and on textured surfaces tape actively will not work because it cannot seal. A well loaded angled brush produces a better line on plaster or patterned paper than tape does. Tape earns its place on smooth gloss trim and against glass.
- How do you paint an uneven ceiling line?
- Paint a straight line rather than following the unevenness, and let the shadow in the corner absorb the difference. Following a wavy junction produces a wavy line that the eye reads as a mistake, where a straight one reads as correct.
- What is the best way to paint skirting boards?
- Mask the floor with tape and film rather than the skirting, since the skirting is the thing being painted. A rigid shield tucked into the gap works on carpet, where tape will not stick to pile. Cut the top edge in by brush and use long strokes along the length.
- How do you paint high ceiling edges safely?
- Use an extension pole with a brush or an edging pad so both feet stay on the floor. If a ladder is unavoidable, move it rather than reaching sideways, since overreaching is the specific movement that causes falls. For a stairwell, hire a platform for a day.
