Sorry to resurrect an old thread, but my late great uncle had his whole living room, dining room and den paneled in 12 inch wide by and actual 1 inch thick knotty pine. When my grandfather was doing the finish work on my uncle’s house, he ordered the panels from a local lumber yard, and made the delivery kid show him each panel before he accepted it. He wound up sending a good quarter of the boards back to the lumber yard for either having loose knots or not enough knots. My grandfather insisted that each panel have at least two and preferably three knots in it. I am told that in the installation of those panels, my grandfather used no power tools. Do not know if that is a fact, but it sounds like him.
The house still stands today, and it current owner, a grand son of my uncle’s, has had many offers to buy that paneling to make his house look more “modern”. He knows better… :-)