There are four grades of birch plywood. Let’s have a look:
A-grade plywood: Being the highest-quality plywood, it is usually the most expensive and has a flawless veneer. Due to its smoothness, it is easy to paint. Order Premium Quality 12mm Birch Plywood
B-grade plywood: It is slightly less smooth than A-grade plywood and has a solid foundation. It usually has minor flaws so it needs some repair.
C-grade plywood: This type of plywood sheets has a few bales up to 1.5 inches in diameter.
D-grade plywood: This grade of plywood is the cheapest. These sheets are usually not repaired. The defect may be slightly larger and the bales in such plywood may be up to 2.5 inches in diameter.