They're also for producing your own make-up.
This video showcases the work of former Harvard Business School student Grace Choi, who has come up with a method to mix your own makeup with the same ink you buy for a commercial printer.
The secret? That's exactly what make-up companies do.
So Choi made her own $300 printer which uses small containers of eyeshadow powder, which are cheap, that can be mixed with printer ink on demand to make your own shades.
It's an unbelievably simple idea, but one that could theoretically make it a lot easier (and less expensive) to try out different types of make-up.