Background: Fiber crafts occupy a vital position in technology innovation and present a promising space for computer science education, which continues to face lopsided participation. It remains unclear whether and how fiber crafts can become a context for computational learning and what role different materials play with the risk to miss computational approaches that could broaden computational cultures. Methods: Fusing constructionist and posthuman perspectives, this study analyzed how middle school students performed computational concepts while weaving and manipulating fabric and how the craft materials drove what could be learned computationally in these contexts. Findings: Present the fiber crafts as a context for performing computational concepts (i.e., variables, conditionals, functions) and that the materials play a role in what can be learned computationally. While weaving drove computing as the performance of automation, fabric manipulation required speculative and physical three-dimensional modeling as computational. Contribution: The paper presents fiber crafts as a promising context for computational learning and theorizes the ongoing material as material syntonicity, contributing a material direction to fostering more inclusive and sustainable computing cultures.