For a pattern board, I use the metal frame real estate for sale signs that are easily found and harvested after dark from the front lawn of a house for sale. It is best to find a "for sale" sign in front of a house that has no "Beware of Large Dog" or "House protected by S&W" signs in yard. The sign itself is secured to the frame by nylon lock ties. They are easy to stick in the ground as the frame has solid metal posts that can be plunged into dirt by placing one's foot on a cross bar provided for that purpose. After removing the sign from the frame, I use the brown (Kraft) paper that is available on what seems like an endless roll from Home Depot. Cut off enough to cover the front of the frame and clip to the frame with clothes pins or the large metal spring clips used to secure documents. Replace paper between shots. The advantage of this type of pattern board is portability and there is no need to splinter plywood or cover up holes.
