Once a slow and reflective handcraft embodying a designer/maker’s skill, mood and imaginations, knitting has been automated through computer-aided design(CAD)and manufacturing technologies (CAM), reducing the role of the textile designer in the processes of textile production. In response, Procedural Knit presents aknit procedural generation machine, designed to enable collaboration between the designer/maker and a computational textile design and production technology. The design of the colorwork knitted pattern isn’t predetermined but created through generative design algorithms influenced in real-time by the designer’s posture during the knitting process. Using this system, we explore the design space of “underdetermined fabrication”, an approach where interactive making systems and procedural rules guide but do not determine the final outcome. Through this system, we raised the question of whether the laborious and repetitive nature of producing knit on semi-automated machines could instead be an integral part of the design-through-making process, similar to other handcrafts such as pottery wherein the potter makes active design choices during the pottery’s fabrication. Furthermore, we uncover how interactive underdetermined fabrication can create room for unpredictable emergent phenomena and aesthetics, and notions of imbuing a “maker’s signature” into the resultant knitted artefacts.