You can do some simple multi-colour work if you knot symmetrically and you have appropriate length threads (one super long base colour, usually). For seldom used colours in the bracelet, it's a bit like multi colour 3D printing with purge-to-infill. You just go back and forth with the background to hide the colour you're going to use later and the background just weaves back and forth over the threads (instead of adding a knot on each thread each time). The knots are the same as usual, but you do a mirror image to reverse the direction. It's less pretty than these, but you can easily do single colour pixel fonts. It requires a bit of planning if you need to move colours around to different columns though.
Fiber arts were definitely the original and oldest "3D printing". Automated looms were computers (with punch cards) well before the rest of computers. My mother has a computer-controlled embroidery machine and it is definitely a "3D printer" to watch it in action. Sometimes I think there's an obvious blindness in the way the term "3D printer" gets used that overlooks a very rich history in textiles (much of that history itself direct predecessors to the same tech).
