Plywood is a structural board consisting of an odd number of thin layers of wood glued together under pressure, with the grain of one layer at right angles to the grain of the adjoining layer. It is one of the most widely used wood products. It is flexible, inexpensive, workable, and re-usable. Plywood is used instead of plain wood because of plywoods resistance to cracking, shrinkage, splitting,twisting and warping. Plywood reduces the tendency of wood to split when nailed at the edges; it reduces expansion and shrinkage, providing improved dimensional stability; It is very hard to bend it perpendicular to the grain direction.