Crochet is still purely manual. While other crafts such as knitting or weaving have received technical support, the process of creating instructions for new crochet patterns is barely supported by domain-specific, digital tools. Those tools are constrained by their underlying crochet pattern languages that are either ambiguous or limited in their expressiveness. As a result, creating crochet instructions requires substantial manual effort and can result in incomplete or ambiguous instructions after all.

We propose a first visual, domain-specific, graph-based language for crochet pattern representation. We show how this language can be leveraged to provide domain-specific tool support by a prototypical implementation of an editor for creating patterns in 2D and viewing them in 3D. In a user study, we demonstrate that the proposed language allows pattern designers to express both 2D and 3D patterns and removes ambiguities observed in current standard notations.