Think of knotty pine paneling as a comfort wood, much as meatloaf and macaroni and cheese qualify as comfort foods. Knotty pine probably peaked in the 1950s, when the light yellow or amber wood -- punctuated by dark red knots -- was protected by a finish of varnish or shellac. Those original finishes may now need to be removed and replaced, but today's stripping technology will make the refinishing process safer and easier than ever before.
Remove any objects from the wall. Place a drop cloth onto the floor adjoining the wall surfaces to protect your flooring from accidental spills.
Open a container of a N-methylpyrrolidone paint and varnish remover.
Apply a thin layer of NMP paste to the entire surface of the paneling, using a disposable paintbrush. Fill any crevices in the paneling.
Leave the paste in place for two hours.
Peel off the old varnish gently without scratching the knotty pine, using a plastic putty knife. Collect the peeled-off residue in a bucket for later disposal.