It's a synthetic wood. OSB, the scientific name of OSB, is a new type of board which came from Europe and developed rapidly in the 1970s and 1980s. The application of OSB in furniture has been developed unprecedentedly. Many large furniture enterprises begin to use OSB to make furniture. The reason why OSB is popular among consumers is that it has no formaldehyde emission, and it is durable, light weight and better flatness than MDF furniture.