PC filament, also known as polycarbonate filament, is known to be one of the strongest materials around because it's immune to impact. In fact, polycarbonate is the most widely used material for making bullet proof glass. The great thing about it is that it can also be used for 3D printing, especially if you want a very sturdy 3D printout.
Aside from that, we also provide PVA filament, which happens to be the easiest to use because it doesn't melt that fast. This one is good for first timers in 3D printing.