Medium density overlay panel or MDO panel, is a paintable surface made of plywood with a weather-resistant resin overlay bonded to the wood by heat and pressure. MDO is valued for its defect-free composition and highly uniform density that allow it to cut, rout, shape and drill cleanly, holding intricate detail with a minimum of waste and tool wear. Developed for signs, Paint finishes on MDO are up to three times more durable than the same finish applied to ordinary plywood.