Interior Painting Step 4: Painting the Trim

Go to Step 5: Touch Up and Clean Up

Time required:

2 to 5 hours for an average size bedroom

Equipment list:


Ready to paint the trim? With the ceiling and walls painted, brushing the trim is the next step in transforming your room and giving everything a nice, finished look. You can achieve excellent results if you follow these instructions.


Start with the windows if they are to be painted. You’ve already prepped the wood by filling the nail holes, sanding, etc. Now you’ll want to tape off the glass with 1.5-inch blue painters tape. A lot of people wonder how best to tape off glass. Basically you trim the tape in each corner at a 90-degree angle with a razor knife, which eliminates the need of tearing tape to any precise length. I demonstrate a quick and easy way in the video.

Another way it to press a sharp multipurpose painter’s tool into the corner of the glass against the tape and tear the tape against the blade. This requires a bit more practice and a sharp tool.

The main thing to remember when painting trim is that you need to avoid leaving “start marks” with your paint brush. This means that you follow a two-step process similar to the process used when rolling walls: First spread the paint on an entire “leg” of the window (or door casing). This is what I call “laying it on.” Second, smooth the paint out with two final brush strokes, each starting in the corner of the opposite end (aligned with the joint) and going toward (and slightly past) the middle of the leg, where you gently lift the brush like a plane taking off from a runway. I call this “laying it off.”

By always doing your final two strokes into the middle like this, you blend your brush strokes together and don’t leave any ugly, streaky start marks in the middle of the trim.

NOTE: Spills and big drips can leak through canvas drop cloths. Wipe them up immediately with a rag.

You’ll need to cut straight lines (some call this “edging”) where the wood meets the wall on the edges of windows and door casings (assuming the wall and trim are different colors). This can be a tricky line to make straight. In my opinion taping the wall is a poor choice because usually the wall is slightly bumpy with texture or other non-uniform features, and you’re going to get a ragged line no matter how hard you push down the tape. Plus you’ll be taping on a wall you recently painted, and in my experience tape does not stick well to fresh paint. Paint takes several weeks to cure, during which time the oils and detergents in the paint slowly evaporate and the paint hardens. But if you just painted the wall a couple days ago, that process hasn’t happened yet, and the surface has a tiny bit of oily residue on it–almost imperceptible, but enough to prevent tape from sticking as well as you would want it to when cutting a straight line.

But here’s the secret to making this line look straight without using tape: Always cheat the line toward the trim. In other words, never let your trim paint creep out onto the wall even a tiny bit, because that waver onto the wall will be very noticeable to somebody standing in the middle of the room. By always keeping the trim paint a hair back away from the wall, you give the illusion of straightness from out in the room. Sure, if somebody walks up and stares directly at the edge of the trim, they might be able to see a little wavering, but nobody is going to do that. They’ll be looking at it from out in the room.

The other trick to cutting this line straight is to keep using the 3-inch angled tip brush (or 2.5-inch angled tip brush) that you used to cut in the room. Don’t get suckered into thinking that a smaller brush is better for precise line cutting, because it’s not, in my opinion. I think a larger brush is more solid and easier to move along in a straight line. You only use the very tips of the bristles to cut the line no matter what size brush you are using, so go for the overall stability of a hefty brush to help you paint a straight line.

Once you paint the windows and door casings, it’s time for the baseboard. First, you will need to mask the carpet or flooring beneath the baseboard with your hand masker using 9-inch paper and 1-inch tape (white tape for carpet, blue tape for hardwood or tile floors). See the video for tips on doing this effectively so you won’t have paint leaking onto the carpet.

Making a straight line where the baseboard meets the wall can be tricky. Once again, it’s a matter of knowing which way you can cheat the line so it will give the illusion of straightness. In this case you do the opposite of what you did on the window and door casings and run the trim paint just a hair up onto the wall. In other words, never leave any wall paint on the top edge of the baseboard, because the baseboard is usually viewed from above and the wall paint will stand out. However, if you run the paint just a hair up ONTO the wall (like 1/32 of an inch), nobody will be able to see that unless they get down on their knees and stare. So by cheating the line up onto the wall just 1/32 or 1/16 of an inch, you can have some wavering in the line but still make it look pretty straight, as long as the entire top edge of the baseboard is painted.

If you have other funky trim elements like chair rail, crown molding, columns, etc., brush them the same way you brushed the windows and door casings, by always starting your final strokes at an edge or corner and laying it off just past the middle before lifting the brush off gently. If you have trim that is too long for that technique, just keep laying on short sections, then do your final lay-off stroke back into your wet edge before moving on to the next section. This will allow your brush strokes to always blend together with your wet paint and you won’t be leaving any streaky start marks in the middle of the trim.

One last important note: Throughout the entire trim-painting process, bring a damp rag along for fixing obvious mistakes in your lines. Wrap the rag around the blade of your 1-inch putty knife or multipurpose painter’s tool and clean mistakes that way; often you can turn a slight waver into a straight line with ease. I’ve always thought the difference between a good painter and a bad painter is that a good painter takes the time to fix his mistakes. And in most cases, it’s easiest to fix them before the paint dries with a damp rag wrapped tightly around the blade of a multipurpose painter’s tool or putty knife.

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