How to Paint Trim to Give Your Walls a Tidy Finishing Touch

Give your doors and windows—as well as baseboards, cornices, moldings, and chair rails—a professional finish with this step-by-step guide on painting trim.

Wall trim adds architectural character to a home and can be painted a contrasting color to grab attention or a neutral shade for subdued interest. However, trim must be properly prepared before being painted. This normally means setting nailheads below the surface of the wood, filling and sanding holes, cleaning, and repairing or replacing damaged wood. It can also require the removal of old paint or varnish to provide a fresh surface for the finish. It's best to have all the preparation work completed on both the trim and the walls before finishing either surface. We'll walk you through the process of painting trim, including baseboards, door trim, crown molding, and more, for a room makeover with a professional finish.

Editor's Note: Be sure to wear protective glasses when stripping, and a dust mask when sanding. Chemical strippers can contain toxic fumes, so ventilate the room adequately before applying the stripping solution. Rubber gloves are also a must to keep the chemicals from burning your hands.

kitchen with yellow cabinets and trim
John Gruen

How to Paint Trim

Learn how to paint baseboards, crown molding, window trim, and more with our step-by-step instructions.

What You'll Need


  • Protective glasses
  • Dust mask
  • Rubber gloves
  • Lead testing kit
  • Orbital sander (optional)
  • Sanding block
  • Hammer
  • Nail set
  • Putty knife
  • Caulking gun (optional)
  • Angled paintbrush
  • Paint tray


  • Drop cloth
  • Painters tape
  • TSP cleaning solution
  • Microfiber cloth
  • 120-grit sandpaper
  • Sponge
  • Wood filler or spackling compound
  • Caulk (option)
  • Primer
  • Paint

Step 1: Test for Lead

Lead is a hazardous material used as an ingredient in paints before the late 1970s. In 1978, legislation banned its use, but your house could still contain lead paint. There are prescribed precautionary steps you should employ in the removal of lead paint, and in some cases, you'll need to call a professional to stabilize or remove these materials.

The best ways to abate lead-paint hazards in your house include:

  • Paint removal: Scrape paint from peeling walls and woodwork with a broad knife. Wear a respirator as you work. You can apply chemical paint strippers to soften the paint. If you dry-scrape the paint, mist the surface with a spray bottle to reduce hazardous dust. Clean dust and particles with a wet mop—vacuuming spreads lead dust. Sanding, sandblasting, and similar methods aren't recommended because of the dust hazard.
  • Encapsulation: Instead of removing the paint, isolate it or seal it off. Apply new drywall over an existing wall or float the wall with wallboard compound.
  • Surface replacement: Remove and replace woodwork and moldings that have been painted with lead paint.

Step 2: Install Trim (Optional) and Prep Area

Unlike other paint projects, you'll want to install the trim before you paint it. Safely secure it to the wall with your desired technique. This step is only for new trim; skip if you're painting a room's existing trim.

Remove furniture from the work area. Lay down a drop cloth that sits right up against the wall of the area you'll be painting. This important step will save your floors or carpet from damage if any paint drips off the trim. Mask off the trim with painters tape.

wiping door frame with towel
Marty Baldwin

Step 3: Clean Surface

Wash the surface of the trim with a TSP solution ($5, The Home Depot), replacing the solution and the rinse water regularly as they become cloudy. Once all trim is clean, rinse thoroughly with a damp cloth and let the trim dry.

Step 4: Sand Trim

Even the best new paints or clear finishes will not adhere well to gloss paints. Prior to painting, scuff-sand all glossy surfaces with 120-grit sandpaper. For flat surfaces, a palm sander or random orbital sander is a great time-saver when sanding. You want to sand with the grain, changing the sandpaper sheet often as it wears down.

Contoured surfaces are difficult to sand with rectangular sanding blocks because they can gouge the wood. Use flexible sanding blocks or sanding sponges to smooth these curved surfaces. If trim was already treated with paint, sand until the surface is no longer shiny.

After scuff sanding, the surface will contain microscopic dust particles left in the grooves by the sandpaper. Pull these particles off the surface with a soft cloth or sponge dampened in water.

Step 5: Fill Nail Holes

If needed, use a nail set to push nailheads below the surface of the wood. Place the point of the nail set in the recess of the nail head and tap sharply with a hammer. Use a putty knife to slightly overfill nail holes, dents, and other damaged areas with interior wood filler or spackling compound. If you'll be painting trim with a clear finish, buy different colors of putty and use the one that most closely matches the finished tone of the wood.

Overfill the area slightly to accommodate its tendency to shrink. Let the filler dry, then sand it smooth with 120-grit sandpaper. If the filler has shrunk below the surface of the wood, reapply another layer and sand it after it's dry. Follow the manufacturer's instructions on your spackling putty or wood filler for best results. Dust off any residue from sanding with a microfiber cloth before painting trim.

If needed, fill any gaps or cracks with caulk, and let dry.

painting baseboard white
Marty Baldwin

Step 6: Prime and Paint

Once you've completed all your prep work, it's time to paint trim. Start by priming trim, making sure to prime any stains and spots you've filled. Let dry for 24 hours. If any spots still show through, apply a second coat of primer and let dry.

Working in sections, paint trim with an angled brush using short brushstrokes. Repeat until the area is complete, then blend the strokes with one long brushstroke that goes the length of the trim. Repeat this process, working in sections until the entire room is complete. Remove painters tape. Let dry completely before you move furniture back into the room.

coffered ceiling with white trim and blue paint
Michael Partenio

Should I Paint My Walls or Trim First?

If you are an amateur painter, paint the trim first with a paintbrush, then the walls. This strategy will make it easier to sand, prepare, and paint all the details, edges, and planes of the trimwork.

After all the coats of paint on the trimwork are thoroughly dry, mask off the trimwork with painters tape and paint the wall with a roller. Because you have masked the trim, any splatters from the wall should land on the painters tape, which will be removed later. Most professional painters would paint the wall first, then skillfully do the trim.

Pick the Right Trim Paint Finish

Choosing the right paint finish for your trim is just as important as properly preparing the wood trim surface. Satin or semi-gloss is the standard paint finish for trim due to its durability. Satin paint will display a light luster with a soft texture. Satin is also more durable than flat paints and can be used for trim that won't get much abuse, especially when you want to set the trim apart from a flat-painted wall.

Doors, windows, and moldings typically take a higher sheen than walls because they get more physical contact and need a tougher surface. In addition, a glossy surface accentuates the woodwork and makes it stand out from the walls. That contrast between trim and walls adds interest to your design scheme. Choose trim paint that's at least one step glossier than the walls.

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