Every good 3D print starts with plastic, usually in the form of colorful strands wound neatly on spools. Though the 3D printing hobby is jampacked with do-it-yourselfers, making your own filament is still out of reach for most home workshops. High-quality filament requires expensive heavy-duty machinery, a lot of space, and a ton of energy.
I’ve had the opportunity to visit three factories making 3D printing filament in person, and a fourth virtually: Prusa Research, Printed Solid, Printerior and ProtoPasta. They all use the same basic principle: mix plastic pellets with color and property enhancing additives; melt it, extrude it, cool it, and wind it on a spool. Easy, right?
