Many people have a traditional inkjet or laser printer in their homes, to print ‘2D’ texts and images on paper. In an extension to this, 3D-printers already show up in our homes, to make gadgets, jewelry and other products. 3D-printing, also known as additive manufacturing is a novel production technique where ‘real 3-dimensional’ products are built layer by layer, made from scratch. This is the opposite of traditional machining operations such as drilling, milling or cutting, where pieces of material are removed to yield the product.