Painting - Straight line on textured wall

Well, I had no idea this would give me so much trouble...
I've already painted a beautiful stenciled vine border in my living/dining room. It's in the middle of the wall and the upper/lower color is merlot. Now I'm trying to paint straight lines to separate the top and bottom of the border from the rest of the wall, and NOTHING is working. I bought a long metal knife, but paint seeps through onto the textured wall. Painter's tape is even worse. Help! I am so frustrated and stuck!

do you have to have the straight lines? i think i'd prefer the more free-form vine by itself being the border, without the added linear element. have you noticed all the scalloped wallpaper borders out there now?

or..........do you mean that you have to have a line above & below the vine, so that you can paint the upper and lower portions of the wall a different color than what's currently behind the vine pattern??? :confused: if that's the case, you're probably going to need to pencil in a line using a straight edge and very carefully & steadily freehand a line.

do you have to have the straight lines? or..........do you mean that you have to have a line above & below the vine, so that you can paint the upper and lower portions of the wall a different color than what's currently behind the vine pattern???
Yes, what are the prupose of the lines; this will determine the best way to do it.

Yes, I need straight lines because the wall is merlot with a faux finished cream-colored border. A green vine is painted on top of the border. So right now it's a somewhat straight line between cream-colored border and merlot wall, and I'm trying to define it more with one of the dark greens in my vine. Is there ANY painter's tape that adheres to the fine texture on the wall?? I have tried really pressing down on regular painter's tape, once it's up, but it still bleeds through. I am at my wits end with this project!

I haven't tried this on a textured wall, but I brush over the edge of the tape with clear glaze (pre-painting) to prevent bleed-through. Some of the regulars here suggest using a little bit of spackle for the same purpose. Try it in a small area and see if it works.

- Millipede

Is the objective to get the tape to stick better to the wall? So, let me see if I understand this - I brush the sticky side edge of the tape with clear glaze, then stick it to the wall? This sounds like a promising idea.
Thanks. Also, what type of glaze should I buy?

M.E.

Not quite. Put the tape on the wall, then apply the glaze/spackle.

What type of glaze?
Should I paint the glaze only on the edges of the tape, or on the whole line which I plan to cover with paint?
Thanks

clear glazing liquid. go to the faux finishing section of Lowe's or an art supply store or any paint store. you just want to apply it over the edge, so you'll be getting some on the tape and some on the wall. you're bridging the edge of the tape. the clear glaze will ooze under the tape (just like your paint did) but since it's clear, you won't see it. and then the glaze will seal over (ie "bridge") the gap where the paint used to go, and keep it from leaking under. or you can do the same thing but with spackle. the spackle is rubbed on with your finger & sort of seals that little gap so no paint can run under the edge of the tape. if you're wanting to paint a thin line that's maybe only 1/2" wide, and you're taping the top & bottom of it, then you'll probably end up just painting or spackling over the whole 1/2" space, plus 1/4" inch up onto each strip of tape.

hope that makes sense now.

clear glazing liquid. go to the faux finishing section of Lowe's or an art supply store or any paint store. you just want to apply it over the edge, so you'll be getting some on the tape and some on the wall. you're bridging the edge of the tape. the clear glaze will ooze under the tape (just like your paint did) but since it's clear, you won't see it. and then the glaze will seal over (ie "bridge") the gap where the paint used to go, and keep it from leaking under.
Yep, what she said. Water based polyurethane will work too.

Thanks everyone!!!!!!

Thanks again...I just wanted to let everyone know that the glazing technique works like a charm. I got perfectly straight lines every time! I plan to use this method when painting my kitchen too.

Thanks!