Plywood is a three-layer or multi-layer board-like material made of wood pieces that are peeled into veneer or sliced into veneer from wood, and then glued with adhesive. Usually, odd-numbered veneers are used and adjacent layers of veneers are used. The fiber direction is perpendicular to each other and glued together. Rotary cut or sliced Okoume veneer is attached to the surface, which is the origin of Okoume plywood. The usual length and width specifications are: 1220×2440mm, and the thickness specifications are generally: 3, 5, 9, 12, 15, 18mm, etc. The main tree species are: beech, camphor, willow, poplar, eucalyptus, etc.