BMW is 3D-printing "finger cots" for some of its factory workers, the German carmaker said this week. Working alongside ergonomics researchers from the Technical University of Munich, BMW uses mobile 3D hand scanners to create tailored thumb-protectors for each worker. The printing is done with a selective laser sintering (SLS) process, using a precisely targeted laser to form a pre-modelled solid mass out of a thermoplastic polyurethane powder. The cots act as splints to counter thumb joint stress, helping workers who are fitting rubber plugs.