3D printing starts by designing objects on a computer and then printing them with thermoplastics (and in this case, lasers) in super-thin layers to create intricate finished objects.
Inside the oven a 30cm-deep basin of powder is heated to just below its melting point; then a laser heats specific points over a layer just 0.1mm deep, melting and fusing the powder. Repeat that 3,000 times – it runs overnight – and you end up with a solid object – glasses, a doll, an architect’s model – surrounded by powder. Wash the powder off, and you have the finished product, with detail as fine as you want. The spectacles’ hinges are held together by 0.5mm links, each just five layers of plastic.
Having got its start in making prototypes for aerospace and automotive companies, and latterly for surgeons looking to make preci