Overview

Painting trim and baseboards covers the wood or MDF molding around floors, doors, and windows, and is a common refresh project for scuffed, yellowed, or chipped trim. It's a great project for someone who already has basic painting supplies and wants crisp, durable lines, since trim uses a harder-wearing paint and more careful masking than wall painting. It suits patient DIYers, since good results depend heavily on sanding, filling, and taping carefully before any paint goes on.

Tools & materials

  • Trim/enamel paint in satin, semi-gloss, or gloss finish
  • Bonding or stain-blocking primer (for bare wood, water stains, or glossy old paint)
  • 2-2.5 inch angled trim brush
  • Sandpaper (80-grit and 120-150 grit) or a sanding sponge for curves and corners
  • Wood filler for dents and gouges, plus a putty knife
  • Paintable caulk and caulk gun for gaps against the wall
  • Painter's tape
  • Tack cloth or lightly damp rag
  • Drop cloths
  • A wide drywall/putty knife or paint shield (optional, to guard the wall while cutting in)
  • Small paint tray or cup

Steps

Tape-and-brush method

  1. Vacuum and wipe down the trim to remove dust, cobwebs, and grime.
  2. Fill dents, nail holes, and gaps with wood filler, let it dry, then sand smooth; caulk the seam between trim and wall.
  3. Sand the whole length of trim — start with 80-grit on rough or heavily painted surfaces, then finish with 120-150 grit to knock down gloss and smooth the surface.
  4. Wipe away all dust with a tack cloth or damp rag.
  5. Apply painter's tape to the wall and floor along the trim, pressing the edge down firmly with a putty knife to seal it and prevent bleed-through.
  6. Spot-prime any bare wood, filled areas, or stains, and prime the whole piece if you're changing from a dark or glossy color.
  7. Cut in a controlled edge with the angled brush, then paint the flat faces in long, smooth strokes, finishing each section with one light pass to even out brush marks.
  8. Let the first coat dry fully per the label, then lightly sand and apply a second coat for full coverage and durability.
  9. Remove the tape carefully while the paint is still slightly soft (or per the tape's instructions) by pulling it back at a shallow angle.
  10. Avoid heavy cleaning or bumping the trim for the first couple of weeks while the paint fully cures.

Scraper-guard method (no tape on floor)

  1. Complete the same cleaning, filling, sanding, and priming steps as above.
  2. Instead of taping the floor, hold a wide, flexible drywall scraper (or plastic paint shield) flat against the top edge of the baseboard.
  3. Paint the top portion of the baseboard with your other hand, keeping the brush bristles riding against the scraper as you move it along, which blocks drips and strokes from reaching the wall or floor.
  4. Move the scraper and brush together in one continuous motion down the length of the baseboard.
  5. Once the top section is done, remove the scraper and carefully paint the lower portion of the baseboard freehand, using slower, controlled strokes near the floor.
  6. Wipe the scraper clean between sections so you don't drag wet paint onto the next stretch.
  7. Apply a second coat the same way once the first has dried.

Safety warnings

  • Work with windows open and a fan running — trim enamel (especially oil-based or bonding primer) can have strong, lingering fumes
  • Wear a dust mask while sanding, particularly with old paint layers, and sweep or vacuum dust rather than stirring it into the air
  • Wear safety glasses when sanding overhead trim like door and window headers
  • If the home was built before 1978, treat old trim paint as a possible lead risk and avoid dry-sanding it (a full lead-safety check is a separate topic)
  • Keep oil-based paints, primers, and rags away from heat sources, and dispose of oily rags per local guidelines since they can spontaneously combust
  • Use a stable ladder or step stool for tall door and window trim rather than standing on furniture

When to call a pro

  • Baseboards or trim show soft, spongy wood, which usually means water damage or rot that needs replacement first
  • You find active termite damage or frass (sawdust-like droppings) near the trim
  • Trim was installed before 1978 and paint is peeling or chalking and you don't want to handle lead testing/abatement yourself
  • You need trim replaced or re-coped at corners rather than just repainted
  • Large sections of crown molding require scaffolding or extension ladders beyond a standard stepladder's safe reach
  • You want a factory-smooth, sprayed finish, which typically requires spray equipment and a fully sealed-off workspace

Cost estimate

Roughly $50-$150 per average room, mainly for a quart to a gallon of trim paint, primer, filler, and tape (less if reusing brushes and a ladder)

Sources