ABS, admittedly the printer/print settings weren't set up as well as they could have been but I don't think that made too much different.
PLA is harder/more brittle than ABS but I think Neil used Nylon (or a variant of) for the clamps.
1:30 in this video shows it's elasticity (apologies for the horrendous music/production quality, it was the first link I clicked) http://digits2widgets.com/3DNylon.html
ABS, admittedly the printer/print settings weren't set up as well as they could have been but I don't think that made too much different.
PLA is harder/more brittle than ABS but I think Neil used Nylon (or a variant of) for the clamps.
1:30 in this video shows it's elasticity (apologies for the horrendous music/production quality, it was the first link I clicked)
http://digits2widgets.com/3DNylon.html