AA – both sides clear, without knots, without sapwood (in the case of oak),uniform/brown color variations;
AB – one side clear, without knots, without sapwood (in the case of oak), uniform/brown color variations. Other side possible small knots and sapwood (in the case of oak), natural color variations, without cracks and other wood creeps;
BB – both side with small knots and sapwood (in the case of oak),natural color variations, without cracks and other wood creeps.