What trim are you talking about? I think if you paint it first, the wood pieces won't join as well. You usually don't glue, but if you are, you obviously can't paint first. If you paint it first, you'll have a harder time puttying the nail holes -- sand paint off around hole, putty, sand again, trying to level putty with paint, repaint. Three good reasons to attach trim first.

Yes, I paint the walls first.

I also paint the trim first, then touch up after it has been installed.

Agree with barbcollins, paint walls first, sand and paint trim before installing. You can fill any nails holes later and touch up with paint as mentioned.

I must have misunderstood your post. I was thinking of the wrong end of the trim, the end that meets the wood frame of the door or window.

Puttying is easier on unpainted wood, but yes, pre-painting the trim means you don't have to carefully tape. That probably saves more time in the long run.

If he won't let you paint first, then he gets to tape off all the trim and then be the one to painstakingly touch up all areas where the paint tape inevitably fails and paint leaches onto your trim.

bahacca-LOL, and I say that because I just finished painting a room (old guestroom) and I know for sure how much the paint has probably leached through the tape . . .

Yes, I gave up on tape a long time ago. Finally learned how to cut in after years of practice.

Now, I need to start wearing reading glasses thought. I swear I cut in nice and clean and look at it from a distance and think it looks terrible. Sucks getting old.

I haven't mastered the tape either. I always get parts where the paint bonds to the taper and the paint rips when the tape is removed. Or the tape doesn't seal well and the paint sneaks under. Eiher way I end up with a very tiny brush doing touch ups.

I laugh when I see those paint commercials where they tape stripes on the wall. 1. Who can get the tape that straight? And 2. how do they get it off that clean and leave a crisp line? I MUST be missing something.

I often do better with a steady hand, depends on what needs paint and what needs to stay clean.

I did recently try out Frog tape and it IS better than the blue stuff.
williamsem-About 10 years ago when we were young and crazy we did an argyle pattern on one of our walls. We painstakeingly measured each corner, etc of every diamond. The key to the peeling off the paint is to do it when it is about 20-30 min into the drying. Where it is wet, but not so wet it will drip and not so dry as to peel off. And if you have textured walls forget about the strips. We have virtually no texture to the walls, so the argyle turned out well. Too bad I don't have pictures of it. It was pretty cool.

If you take a credit card and smooth down the tape edges,
then put a stripe of paint along the tape edges, first, and it kind of seals it. As bahacca mentioned, pull it off before the tape dries?
You're good.

However, I cannot figure out how they get those straight lines. And don't tell me they draw them with a level or laser or something. You still have to stick the tape along the line.

I think I'd paint my woodwork first. Actually, when I get trim, molding and woodwork, I will paint it first because I can't hold a straight line to cut in. I can touch up nail places more easily because they don't require dexterity or steady hands. :)

Oooooh, argyle! Sounds awesome! My problem is I usually do 2 coats of paint. Maybe I just need to learn to be happy with one?

No williamsem - you learn to tape twice. =) I did a cool stripe around a kitchen one time. Fairly smooth plaster walls which helped. So it was tape, paint, remove tape, dry, retape, paint, remove tape. Ta-da! Cool stripe with a razor sharp edge.

And, depending upon what trim we are talking about.. what others have said. Paint both, put up trim, patch nail holes, touch-up nail holes and any other imperfections. :)

Since we're weaving off topic, I painted a checkerboard of five different colors on the wall behind our kitchen table in the pre-reno house. When we put the wall in, I knew I wanted to do something interesting on that wall so I had the drywallers use a flat texture. At least that made taping easier. BUT...with this pattern, you can't paint two squares next to each other at any one time. Needless to say, this project was tape-intensive, but I powered through it in a couple of days.

I didn't paint the area in the bottom center of the wall as our banquette bench was installed there.

Regarding crisp lines on stripes, the experts say to paint your wall your base color, then tape, then paint your base color over the parts to be painted a different color, THEN paint your second color. If anything seeps under the tape, it's the first color, and that paint over the tape will keep your second color from seeping.

Answering OP's question, I always paint walls then attach the trim, which I've pre-primed and painted. Do the touch-ups when you're caulking the edges of the trim.

Another vote for paint the trim outside and then bring it in and nail it on. We've done it both ways and painting outside is so much easier. A little putty and a paint-over is easy.

Sorry for the confusion, that's what I get for posting so late. Yes, I was talking about walls. Dh gets in a hurry to get his part done and thinks I can just work (or paint) around it. I hate cutting in, and it looks so much better when there aren't brush marks around all the trim.

I have no idea what color I even want in there.