MDF (medium-density fiberboard) is an engineered wood product formed by breaking down hardwood or softwood residues into wood fibers, often in a defibrillator, combining it with wax and a resin binder, and forming panels by applying temperature and high pressure. MDF is denser than plywood. It is made up of separate fibers, but can be used as a building material similar to plywood. It is stronger and much denser than regular particle board. The grain and color may vary from sheet to sheet.