Plywood was invented about 3400 B.C. by the Ancient Mesopotamians, who attached several thinner layers of wood together to make one thick layer. They originally did this during a shortage of quality wood, gluing very thin layers of quality wood over lesser-quality wood.
Modern plywood was invented, in the 19th century, by Immanuel Nobel, father of Alfred Nobel. Nobel realized that several thinner layers of wood bonded together would be stronger than one single thick layer of wood, and invented the rotary lathe used in plywood manufacturing.
The plywood manufacturing process begins with processing the wood at the sawmill. When the raw logs are delivered to the mill, they are sorted, typically by size and species of tree.
Plywood can be made with a large variety of types of wood. It is often made with Gurjan pine, Keruing, Eucalyptus, Poplar. The uncut logs are then treated with water. They may be soaked in hot water, exposed to steam or sprayed with hot water, depending on the set up of the particular mill. Following this log conditioning, the bark must be removed from the logs to accomodate the lathing process. The logs are then cut to a length appropriate the mill's lathe.
The process is explained in the picture on the right.