Hardwood Plywood – For your high-quality projects. • 1/4” Birch is good on only one side with a lauan back, similar to A-3 grade. • 1/2” Birch is a C-2 grade, cabinet grade finished on both sides. • 3/4” Birch is good on both sides, A-2 grade. • 3/4” Oak is good on both sides, A-2 grade.