What kind of material was used for the cold casting of the original Jango armor?

I'd assume the only material possible for cold casting would be resin, no?
Although in some shots, you can actually see the armor bend! I guess this would probably be "stunt" armor as I strongly doubt the armor that's been on display at exhibits and such could bend like this (could be wrong). Really not sure what the stuff was.


^^^ Bending armor ^^^

Just realized, I never posted the final product!

Here it is,






And compared to the MR Boba. Big size difference.

nice work!