Hello, I am planning to renovate a summer cottage that has wainscoting on half the wall and wallpaper above. There is thin plywood in the wall above. I would now like to install new panels above the wainscoting that I can then paint. What's important is that these panels aren't too thick, so they don't reach the level of the wainscoting (i.e., don't stick out as much). I also want panels that are good for screwing things into.
Does anyone have a good suggestion for what type of panels I should use that will be easy to work with for painting and achieving a smooth wall, but still sturdy enough for screws, without being too thick?