Short answer
Clean and lightly sand the trim, fill nail holes, caulk gaps to the wall, and prime bare wood, filler and MDF edges. Then brush on two thin coats of a trim enamel in satin or semi-gloss with a 2 in angled brush, sanding lightly between coats. Tape the wall, not the trim, and pull the tape while the last coat is still soft.
What you need
- Trim enamel, satin or semi-gloss waterborne enamels level well and clean up with waterFind it
- 2 in angled sash brush for the profile and edgesFind it
- Primer for bare wood, filler and MDF edgesFind it
- Painter tape for the wall edgeFind it
- Fine sanding sponge between coatsFind it
- Paintable caulk and wood filler before primingFind it
Step by step
Clean
Wipe the trim down to remove dust and hand grease. Paint does not stick to grime, and door casing collects a lot of it.
Sand
Scuff glossy old paint with a fine sanding sponge so the fresh coat can grip. Sand any rough filler flush.
Fill and caulk
Fill nail holes with wood filler and let it dry. Run a thin bead of paintable caulk where the casing meets the wall, then smooth it with a damp finger.
Prime
Prime bare wood, filler patches and any cut MDF edges. MDF edges soak up paint and go fuzzy without primer.
Tape the wall
If the walls are finished, tape the wall right at the casing edge and press it down firmly.
First coat
Brush the profile and edges first, then lay off long strokes along the length of each piece, keeping a wet edge so laps do not show.
Sand lightly and recoat
Once dry, sand very lightly, wipe off the dust, and apply a second thin coat. Thin coats level better than one heavy coat.
Pull the tape
Pull the tape at a low angle while the last coat is still soft, for a crisp line.
Sheen and color
- Satin is softer looking and hides small flaws; semi-gloss is tougher and wipes cleaner. Sherwin-Williams shows a project with semi-gloss on the doors and satin on the trim, taped off from each other (Sherwin-Williams).
- White is the default; dark trim frames the doorway; trim in the wall color reads modern. Ideas in door molding ideas.
- PVC trim takes acrylic latex; use a vinyl-safe paint for dark colors, as Westlake Royal advises for its PVC brick mould.
Installing first? See how to install door casing. Choosing a material that paints well: MDF vs pine vs PVC.
Questions people ask
What sheen is best for door trim?
Satin or semi-gloss. Both wipe clean and stand up to scuffs better than flat or eggshell. Sherwin-Williams shows one project using semi-gloss on doors and satin on trim. Glossier sheens show surface flaws more, so prep matters more.
Do I need to prime door trim?
Prime bare wood, patched areas, filler and cut MDF edges. Factory-primed trim that is clean and sound can usually take paint directly, but any spot you sand through needs primer.
Should I paint trim or walls first?
Many painters do trim first, then cut the wall in to it, because a straight wall line is easier to brush than taping trim. Others paint walls first and tape them. Pick one order and stick with it.
Sources
Last reviewed October 12, 2026. Profiles, sizes and listings change; check the product details before you buy, and follow the maker’s instructions.