[Stefan] from CNC Kitchen explored an unusual approach to a multi-material print by making custom PLA filament with a TPU core to make it super-tough. TPU is a flexible filament whereas PLA is hard ...

There was a time when most 3D printers used ABS plastic. It stinks, is probably bad for you, and tends to warp unless printed in a heated enclosure. So most people have gone to something else, mostly ...