The strongest, lightest, most versatile utility and decorative product made from a renewable resource, plywood is kilo for kilo stronger than steel. Plywood was the first type of engineered wood to be invented. It is made from thin sheets of wood veneer, called ply or veneers. These are stacked together with the grain direction of the ply differing from its neighbours’ by 90 degrees (cross banding). The ply layers are bonded under heat and pressure with strong adhesives, usually phenol formaldehyde resin, making plywood a type of composite material. Laminating an odd number of ply sheets (3,5,7…) reduces warping, while increasing the number of ply layers increases the resistance to shearing forces. A common reason for using plywood instead of plain wood is its resistance to cracking, shrinkage, twisting/warping, and its general high degree of strength.