UltraStock-Free MDF by Temple-Inland has no added urea formaldehyde, meaning that it contains only trace amounts naturally found in the wood-fiber ingredient itself. Use of the product counts toward various green-building program credits. Sheets from 1„4 inch to 15„16 inches thick are available in dimensions up to 5 feet wide and 16 feet long. Expect to pay about $30 for a 3/4-inch-thick sheet in a standard 49-by-97-inch size. Temple-Inland, 800/231-6060, templeinland.com.