Particle board, also known as chipboard or low-density fiberboard, is an engineered wood product manufactured from wood chips and a synthetic resin or other suitable binder, which is pressed and extruded. Particle board is often confused with oriented strand board (OSB, also known as flakeboard, or waferboard), a different type of fiberboard that uses machined wood flakes and offers more strength. Characteristics Particle board 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. Particleboard can be made more appealing by painting or the use of wood veneers on visible surfaces. Though it is denser than conventional wood, it is the lightest and weakest type of fiberboard, except for insulation board. Medium-density fibreboard and hardboard, also called high-density fiberboard, are stronger and denser than particleboard. Different grades of particleboard have different densities, with higher density connoting greater strength and greater resistance to failure of screw fasteners. A significant disadvantage of particleboard is its susceptibility to expansion and discoloration from moisture absorption, particularly when it is not covered with paint or another sealer. Therefore, it is rarely used outdoors or in places where there are high levels of moisture, except in bathrooms, kitchens and laundries, where it is commonly used as an underlayment shielded beneath a moisture resistant continuous sheet of vinyl flooring. In dry environments, veneered particleboard is preferred over veneered plywood because of its stability, lower cost, and convenience. History and development Particleboard originated in Germany. It was first produced in 1887, when Hubbard made so-called "artificial wood" from wood flour and an adhesive based on albumin, which was consolidated under high temperature and pressure. During the Second World War, phenolic resin was more readily accessible than top-grade wood veneer in Germany, and Luftwaffe pilot and inventor Max Himmelheber played a role in making the first sheets of particleboard, which were little more than pourings of floor sweepings, wood chips, and ground-up off-cuts and glue. The first commercial piece was produced during the Second World War at a factory in Bremen, Germany. For its production, waste material was used, such as planer shavings, off-cuts or sawdust, hammer-milled into chips and bound together with a phenolic resin. Hammer-milling involves smashing material into smaller and smaller pieces until they can pass through a screen. Most other early particleboard manufacturers used similar processes, though often with slightly