Step 1: 3D modeling

Making of Magnetic Duckling 3D
(click to enlarge)

The doll is modeled on Zbrush, a software that lets us sculpt using the pressure of the pen on the tablet using virtual tools, that same you'd be sculpting with real tools. We make a rough model that we refine until it is detailed enough.
Using this method, we can't test the joints or balance of the doll. It is hard to know if the thickness of the piece will be able to withstand the pressure of the elastics. It makes it hard to know before printing if the doll will properly bend. And as you can imagine, it rarely is the case.