Birch faced plywood is made using solid birch veneer. The final finish is provided by quality birch veneer overlaid on both sides. The thin layers are also known as 'piles' and they are glued together. When another layer is added, the wood grain will be rotated 90 degrees before being glued. This process is called cross-graining and its main motive is to reduce splitting, expansion, and shrinkage. The outer layers of plywood panels will always be birch, but sometimes the inner layers are replaced with other woods making the resulting panels lighter and cheaper. 18mm Birch Plywood