skCAD: A Design Tool for Solid Knitting with Automatic Pattern Generation

Solid knitting is a fabrication technique for producing dense 3D volumes through knitting. Designing such objects is difficult because yarn paths must remain continuous—formed from one (or a few) yarn(s)—while handling increases and decreases across three dimensions. To address this challenge, we introduce skCAD, a block-based design tool that allows users to compose 3D forms by stacking rectangular blocks, which are then automatically converted into solid-knitting patterns. To build skCAD, we also standardized a grammar of solid knitting that formalizes stitch and row operations, making it possible to construct patterns beyond basic shapes. Our tool and grammar enable the creation of complex solid-knitted objects, and help those interested to learn and explore this technique. We evaluated the system in a workshop with knitters, yielding insights into design needs and directions for future development.