Since I printed my first 3D printing model with Geeetech 3D printer, a question came out from my brain. We can print metal, we can print wood, we can print organ, we can print food, etc. My Geeetech 3D printer, for example, a cheap printer, can print many models with 5 different types of material ! What else can we print with a 3D printer? or we can put forward another question, what the 3D printer can not print ?