It is printed in white nylon and then hand painted. It is amazing to think that one day we might be able to print out exactly what models and model parts we want, something I appreciate as I struggle to lay my hands on some of the rarer vehicles that were in service with the Finnish army in WW2.
Of course, we should not forget that however 3D printers evolve over the next few years you will still require adept 3D designers to crete the software models first. I've tried to get into 3D design and I appreciate that it is an art in itself.
Above: My feeble attempts at 3D modelling. I created this Vickers tank some years ago now and found even this simple shape very time consuming and I haven't even added a lot of the smaller details.
Link: Shapeways 3D printing - Amazing Hand Painted, 3D Printed Miniatures