Installing Beadboard paneling
You can cut your beadboard out of square in the corners and caulk the gap if it's small enough. If that isn't an option, I usually use screen mold for trim. It's a flat trim 3/4" wide (with both edges) rounded and about 1/4" thick so it will sit on top of standard baseboard without protruding more than perhaps 1/8". Depending on how the corners turn out, you may get by with just one piece or you can put a piece on both sides of the corner.....
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