Primer for paneling

I've been in the painting business for over twenty five years and have never heard of a paint with paste consistency that fills paneling grooves, BUT, that doesn't mean it doesn't exist. I prefer to use an oil-based wood primer (NOT KILZ) followed by two topcoats of satin or semi-gloss oil based paint. The grooves look fine. I have used spackling before to fill the grooves but for the time and effort, it would be better to remove the paneling. HTH

If that primer existed it would be like rolling on texture. Clean well if wax or polish was ever used and use oil primer.

Takes more time than its worth but you can use dap plastic wood or spackle or drywall mud with lots of sanding. Consider removing panneling and doing 180 and then paint. use good oil or shallac primer. s

Yeah, an oil-based primer is correct, after you're sure the surface is clean. But I wouldn't bother with an oil-based finish coat -- if you or someone else wants to paint it again later you have to stick with oil-based finish, or use an oil-based primer in order to switch to a latex finish.

I've never heard of a primer specifically for paneling, but maybe it exists. Seems to me, though, that would be an exceptionally narrow market. Not many people have paneling anymore, or want to paint it.

If you're intent on filling the grooves, keep in mind that there's a chance they'll look different than the paneling. Even through a primer and 2 finish coats, the paneling can show a wood texture. The grooves won't.