Voids are on both sides :( Basically, the middle of the board was bad. Those pieces were super brittle too.
The hardwood place agreed that wasnít right. They gave me a free slightly longer/wider piece of walnut to make sure I got a good section. I bought a 2nd big piece of maple for $30, and now I have enough to make a 2nd board. I think Iíll actually go edge grain on this one, as itíll be slightly easier to make and I learned that itíll be used less for cutting and more for like putting bread on and serving and other things. Also, I read that edge will be less prone to warping even though itís not as good for self healing/knife care.
As a bonus, this was a big board (18◊24) and half the pieces had these defects, so I still managed an 18◊13 end grain board out of this, so now I have two :)
As far as the walnut and open-grain, I did notice that as well. I have seen a few designs where it was all maple and the walnut was decorative on the outside. Maybe that's why?