Painting - Trim work

I am paining an entry wall with rounded corners. The base is a satin (beige)and the trim is a semi-gloss(off-white). So far I have painted the walls, now I need to work on the trim. The area is rounded and flat where the 2 colors meet, so preciseness is of the essence. I masked off to do the base color now I am leery to mask off to the trim, I don’t want to pull off the new paint. All other trim work will be fairly easy because they all have more of a sharp corner. This is the one area that will be difficult because its smooth and flat. I could just paint it free hand and pray that I don’t run into the base paint, but I am hoping that their is something I can do to prevent any accidents because its on a main wall, and most visible. Any suggestions?
I sure hope this makes sense... :o

Most painters will free hand the baseboard trim. And yes the tape runs a good chance of pulling off the fresh (wall) paint. You can buy a carpet sheild that has a thin metal blade about 18" long. Hold this above the moulding, against the wall to protect it. Keep a wet rag and bucket of water to wipe the metal edge down and clear off any paint that gets on the sheild otherwise eventually it transfers from the bottom edge and back of the sheild onto the wall.

What if I tacked up a piece of masking paper then lightly rubbed a layer of spackling along the edge?
I am sitting here staring at trying to figure something out. I am scared to death to try this free handed.

Shoulda painted the trim first?????????. Try This on one side of one door or window. take the tape and apply it to something to remove the tack put it on the paint and go like hell then remove the tape immediately. Pull the tape off starting at the top and pull down slowly toward the floor NOT out toward you.

The trim is old and covered with a dark varnish/stain product. The initial plan was to paint it white...yeah right. :eek: Replacing the trim is not feasable. If painting this trim with white satin is...to be done, are there any suggestions as to getting a neat and complete paint finish? However...I figure the best solution is ----- if it aint broke, dont fix it ----- meaning restain the darn trim and leave well enough alone. :D

Any comments and or suggestions welcome

"The trim is NOT old and covered with a dark varnish/stain product. The initial plan was to paint it white...yeah right." No.
Its already white, actually I am painting it the same way it was before, same color etc. It hasn’t been painted in 6yrs and since its the entrance to the kitchen it definitely needs painted. Maybe I am saying the wrong term. Its not (technically) trim, its part of the wall. When you walk into my kitchen you walk through, like a door way, that’s what I am calling an entry way. I want that entry way painted like trim, everyone puts their hands on it ect. Its textured just like the walls, I believe knockout is the right texture term. I am trying to be consistent in what I paint white versus what I paint beige. I want all the doors, baseboards, pop-outs, ceilings, to be an off white, the base walls beige. Since I dont have a baseboard that divides the trim from the wall, I am trying to create the illusion that this trimmed off. Does that make any sense??
As for painting it first, everyone and everything I have read says you should paint the trim last.

I was asking about a project I am working on

Usually a color change on the same wall is either at a concave or convex corner. It's a kind of confusing trying to picture in the mind exactly what you are trying to achieve. The picture that I get is that you have a rounded vertical wall corner that you wish to paint as if it was a trim piece but because it's really wall, you have no edge to guide you.? Have you considered adding a slim piece of vertical moulding that would be painted with your trim color and also act as a permanent guide for painting the corner wall too?
Just a suggestion ;)

Yes, one would save the trim for last. But we are not really dealing with trim here. Essentially, you want to paint a stripe on a newly painted wall.

The blue painters tape should work. Tape it off, then burnish the edge to prevent bleeding under the tape. As soon as you paint the stripe, remove the tape.