Chipboard otherwise known as particle board is an engineered wood product manufactured from wood chips, sawmill shavings, or even sawdust and a synthetic resin or other suitable binder, which is pressed and extruded. It is cheaper, denser and more uniform than conventional wood and plywood and is substituted for them when cost is more important than strength and appearance. It is often made more appealing by painting or by using wood veneers on visible surfaces. Different grades of particleboard have different densities, with higher density connoting greater strength and greater resistance to failure of screw fasteners. A significant disadvantage, is susceptibility to expansion and discoloration from moisture absorption, particularly when it is not covered with paint or another sealer. In dry environments, veneered particleboard is preferred over veneered plywood because of its stability, lower cost, and convenience.