G-11 is glass-filled epoxy, similar to G-10 but with more glass which makes it stronger.
The strongest handle material is unquestionably steel -- make the knife all in one piece. The same applies to folding knives as to real knives; a steel handle is unquestionably the strongest, but obviously the joint is the weak point anyway; there's no point in going overboard strengthening one link of a chain.
The trouble with steel is the weight. If you make it big enough to fill the hand it's going to be very heavy even with holes drilled in it, and if you make it thin enough to balance the blade it's not going to be pleasant to work with for long at a time -- strength isn't the only consideration in choosing a handle material.
Wrapping the handle of an all-steel knife is one solution, but paracord wrapping is not the most durable kind of handle around -- though many of us don't care because we can rewrap it in just a couple of minutes.
I like to wrap with continuous half hitches, using mason's cord which is much smaller than paracord. The knots make a spiral pattern that aids grip, and it holds up much better than a plain wrap.
Then there are Mad Dog's bulletproof handles. He uses a glass-filled epoxy that's even stronger than G-11. If I recall the test correctly, pistol bullets bounced off with barely noticeable surface damage and a high-powered rifle bullet wreaked havoc -- that's comparable to bullet-proof vests. Solid steel is even stronger, of course, but that's strong enough for most of us.
-Cougar Allen :{)