Three-dimensional (3D) printing, also known as additive manufacturing or rapid prototyping, is the process of creating three-dimensional objects from digital files. Working on one layer at a time, 3D ...

Yes, 3D pens really work, if what you want to do is create a 3D model by hand. If you want to create a 3D model based on a pre-existing design, though, you need a 3D printer.