In a workshop that’s a refuge from the world, Dorothea Campbell uses her hands. Her right hand turns a crank, or manipulates dozens of needles arranged in a circle. With her left, she holds tightly to ...

3D printing is great if you need to create something made of plastic or even metal or ceramic out of thin air. But what if you want something fuzzier and warmer? Something, like say, a hand-knit scarf ...