The doom and gloom over climate change and ecological collapse does have one silver lining: the high numbers of plastic bottles that we’re currently throwing away into landfill, or rivers and seas, are a brilliant potential source of 3D printing filament. Polyethylene terephthalate, or PET as it’s abbreviated, is strong, light, non-reactive, and is a barrier to oxygen, which is the molecule that among other things enables bacteria to turn beer into vinegar. It’s an incredibly useful material in food packaging for all these reasons, and in its modified form of PETG, it’s also widely used in 3D printing. Igor Tylman has built a machine that can reliably turn empty PET bottles into 3D printing filament, potentially turning rubbish into gold. There’s no place on Earth that doesn’t have an excess of plastic bottles, so this technology really could lower the entry barriers to 3D printing for many people. It’s pretty simple: the rotating bottle is continuously sliced into a single thin strip which runs through a heater to shape it into a consistent 1.75mm wide filament.