I've used MDO signboard for lids for many years. It's heavy, but lasts forever, and doesn't warp. I cover my truck bed with used signboard--salvaged from the large full-sheet commercial real estate for sale signs. It's generally well painted, and lasts again for many years of hard use on a truck bed. You just have to look at the message on the sign year after year. Randy Oliver -- Visit www.honeybeeworld.com/bee-l for rules, FAQ and other info ---