And On With the New: How to Paint Corners and Trim Like a Pro

Painting a clean, flat wall is pretty easy. It’s the corners, edges and funny angles that give you trouble. If you’ve ever wondered how to paint corners and trim without wobbly lines, drips and smudges on the ceiling, the good news is that it’s mostly about the right tools and a few simple habits.

Whether you’re freshening up a bedroom in Fishtown or painting the trim on a Haddonfield colonial, these tips will help your work look professional.

Start with the right brushes (yes, more than one)

You can’t get into every little crack and crevice with a thick, wide brush. Plan on owning a few:

• 1- to 1.5-inch angled brush: For window muntins, spindles, narrow trim and tight corners.
• 2- to 2.5-inch angled sash brush: The workhorse for cutting in along ceilings, corners and baseboards.
• 3- to 4-inch flat brush: For wide trim boards, doors and areas a roller won’t paint well.

For latex paint, choose synthetic (nylon/polyester) bristles. For oil-based paint, natural bristles work best. A quality brush holds more paint, leaves fewer marks and lasts for years if you clean it properly.

Prep the surface for a smooth finish

Good painting starts before you open the can.

1. Fill and patch. Fill nail holes and small dings with spackle. For bigger cracks or damaged drywall, patch properly and let it dry.
2. Sand smooth. For a professional-looking finish, sand any rough edges left from scraping or patching. Use 120- to 150-grit paper on walls and 180- to 220-grit on trim between coats.
3. Clean. Wipe down trim and walls to remove dust. Kitchen walls and trim often need a degreasing cleaner first.
4. Caulk. Run a thin bead of paintable caulk where trim meets the wall and in trim joints. It hides gaps and makes your lines look crisp.
5. Tape if you need to. Painter’s tape helps beginners, but press the edges down firmly. Remove it while the paint is still slightly wet, pulling at a 45-degree angle.

How to paint corners and edges: cutting in step by step

“Cutting in” means brushing a neat band of paint along edges where a roller can’t reach. Here’s the technique:

1. Load the brush lightly. Dip only the bottom third of the bristles, then tap (don’t wipe) both sides against the inside of the can or bucket.
2. Start slightly away from the edge. Place the brush about half an inch from the line and make a short stroke to unload some paint.
3. Work toward the line. With the brush’s narrow edge leading, press gently so the bristles fan out, and glide along the edge in one smooth stroke. Let the bristles do the work.
4. Feather it out. Brush the band out a few inches wide so it blends with the rolled section.
5. Keep a wet edge. Cut in one wall at a time, then roll it right away, so the brushed and rolled paint blend instead of drying as separate bands.

Inside corners

Paint one side of the corner, pushing the bristles slightly into the corner, then do the other side. Don’t overload the brush, or paint will pool and drip down the corner.

Ceilings

If you’re painting the ceiling too, do it first. A tiny bit of wall color creeping onto the ceiling is much easier to fix with a wall-colored cut line than the other way around.

Rolling without fuzz, lines or lap marks

• Prep the roller. If you use a high-quality roller, you shouldn’t have much trouble with “roller fuzz,” the loose fibers that get stuck in your paint. To be sure, wrap masking tape around your hand, sticky side out, and dab it all over the dry roller before painting.
• Pick the right nap. Use 3/8-inch nap for smooth walls, 1/2-inch for lightly textured surfaces and a short foam or microfiber roller for doors and trim.
• Roll in a “W” pattern. Then fill it in without lifting the roller, and finish with light, straight strokes in one direction.
• Don’t press too hard. Heavy pressure squeezes paint out the ends of the roller and leaves ridges.

Painting trim and doors

Trim usually gets a semi-gloss or satin finish because it’s durable and easy to clean. A few tips:

• Paint trim after the walls if you’re doing both, so you can cut a sharp line onto the trim.
• Apply thin coats. Thick coats sag and drip on vertical trim.
• For paneled doors, paint the panels first, then the horizontal rails, then the vertical stiles.
• Lightly sand with fine paper between coats for a glass-smooth result.

Seasonal and comfort tips

In humid Philadelphia summers, paint dries more slowly and can stay tacky, so run the AC or a dehumidifier and allow extra time between coats. In winter, keep the room above 50°F and use ventilation that doesn’t let the room get too cold. Low-VOC paints make indoor work more pleasant year-round.

Safety notes

• Ventilate well with open windows or a fan blowing outward.
• Use a sturdy step ladder rather than standing on chairs or buckets.
• In homes built before 1978, test for lead before sanding old trim. Many older Philadelphia homes still have lead paint on windows and woodwork.
• Store oily rags (from oil-based paint or stain) flat to dry outdoors or in a sealed metal container with water. They can self-ignite.

When to call a pro

Some painting projects are worth handing off, especially when there’s repair work involved or the details are extensive. Consider a pro if:

• Walls have cracks, holes or water damage that need drywall repair first
• Trim is split, rotted or missing and needs carpentry work
• You’re painting high ceilings, stairwells or lots of detailed millwork
• You want a flawless finish on cabinets, doors or trim

Our team does interior and exterior painting throughout Philadelphia and South Jersey, and we take care of the prep and repairs that make a paint job last. Request a quote and tell us about your project.