I have been using cutting boards I bought at Bed Bath & Beyond for the last 10 or 12 trips to Sun n Fun and Oshkosh. 12 x 8 for the mains and 6.5 x 8.5 for the nose. They are still holding up fine and definitely help keep my Cherokee 6 from sinking in after a week of camping.
Spent two of the most amazing, informative, and fun days of my life with Greg Koontz last October flying out of his Sky Country Ranch B&B. Not only is he an excellent aerobatic instructor, he and his wife make you feel like family.