3D printing, also known as additive manufacturing, is the exact opposite of the traditional way of making objects. Instead of machining or "subtracting" material to form an object - much like how a sculptor cuts away clay - 3D printing adds layer upon layer of material to build an object. Product designers and engineers upload a digital (CAD) file to a 3D printer, which then prints a solid 3D object.

Thermoplastics are the most frequently used materials, but the technology also includes photopolymers, epoxy resins, metals, and more. Cutting-edge bioinks, which use a mixture of human cells and gelatin, have also been leveraged to 3D print complex tissue models. Even edible materials such as chocolate are being used in 3D printers.