I have successfully painted several rooms of "regular", smooth finish paneling. I like the look, and even kept the grooves. However, I have one room I want to paint which as a more rustic type of paneling. It is more like boards, and has a bit of rough surface. It's a fairly dark wood, and I'd like to either make it look weathered by staining, or paint it. In both cases, I'd be using a gray color. I don't want to sand the walls - what's the best way to go?
You will not be able to stain the paneling unless there is no finish on it. You will want to make sure the paneling is clean and free of any wax. If this is real wood paneling and not the sheet type, then you will want to prime with a shellac based primer such as Zinsser BIN. This primer will hold back the knots in real wood paneling. The finsh paint can be the acrylic latex topcoat of your choice.
If you paint this with an eggshell or better yet, a semi-gloss paint, a "glazing liquid" or graining liquid can be tinted (not mixed with paint!) and then brushed over the cured paint to highlight the grain. Oil based liquids are easiest to work with. Brush or roll the liquid on and brush through with a dry brush until it sets up then move on to the next section and repeat.
I am rather curious what type of furniture you would put in a room like this, and would love it if you could share the photo of the finished room because it sounds like an interesting idea to have your walls done this way!