Hello all, I'd like a suggestion, I have a 3D printed phone case that I made with Shapeways, we used "Black detail" but the parts came back too flexible. We intend on using Polycarbonate with a percentage of glass fiber for regidity in the finished product. However we need to make a few "testers" to send out to people. Shapeways suggested Alumide or "Grey Robust". However, I'm worried that Alumide is too brittle, and Grey Robust won't have the detail needed in a small part like a phone case. I guess I could sand the rough edged of "Grey Robust" if it's an issue, what do you guys think?