I just finished shooting my latest bow creation. It is a 3-piece take down bow. I have made the limbs re-curved. To do that, I made a form out of solid foam and used clamps to hold the wood laminates to the shape.
The back has two layers of glass fabric on the outer 1/8" laminate. Then I added one layer of glass mat to the second, 3/64" middle layer. That was Titebonded to the belly 1/8" layer. So, 3 layers. The bow shoots crisply and it pulls 43#. I have an earlier pair of limbs which have a weaker pull weight. That is why I added the inner layer of mat.
I need to cut some more Hickory for the next set of limbs. When I do, I will experiment with a thicker belly piece, and a thicker back piece. If I add about a 1/16th more wood, I should be right at 50# pull.