birch plywood15mm plywood18mm film faced plywoodbrown film faced plywoodfilm faced plywoodblockboard plywoodcommercial plywoodbirch plywood for sale18mm birch plywoodblack film faced plywood12mm birch plywoodmr poplar plywoodwbp poplar plywoodfurniture quality plywoodMineral deposits (also called pitch pockets or sap pockets) are very little black