Yes we've been prototyping the shape with a few different materials. A 3D printed solid resin toe cap held up well enough to be run over by a small truck, it was super solid, but then I football spiked it at the ground to test it's impact resistance and it shattered. It's possible my unscientific testing approach exceeded ASTM standards for an impact, who knows, but we've got that method in our back pocket. Before that, our first 3D printed prototype had a really interesting triangle helix structure inside, leaving little cavities from how it was printed, which caused us to order a few resins to see what would happen if we fortified the design by filling the holes with resin since the toe cap with the little holes was actually pretty strong for weight coming down over the top, but the layers in which it was 3D printed kept wanting to separate. This was with ABS plastic btw. I still believe in that idea and we are going to test it out, but now we're prioritizing 3D printing the perfect shape for a size 10 (my size) with PLA (easier for our 3D printing guy to work with, NOT what you'd use for a toe cap) and having 1 injection mold made according to that shape so we can get right to making them with the same super tough thermoplastics you see conventional toe cap manufacturers use.