The textile industry is increasingly seeking materials within a circular economy framework to mitigate waste and foster regenerative ecosystems. Design education is concurrently evolving, challenging designers to make progressive and sustainable choices in product selection. Integrating circular economy principles with material selection involvers categorizing materials into biological and technical cycles, each governed by specific paraments such as safe cycles, longevity, and end-of-life considerations. This study focuses on the principle of eco-design, often linked to reducing the ecological footprint. Sustainability and circular economy principles are examined, encompassing various aspects related to materials and processes, including upcycling, downcycling, cascade use, safe loops, durable products, natural cycles, bio-neutrality, plastic-free solutions, and lower CO2 emissions. A comprehensive literature of scientific works on biomaterials for textile application is conducted, and insights are disseminated through interviews with Portuguese designers and researchers who specialize in these materials. Employing exploratory and generative methods, this research proposes an exercise termed the Circular Network, designed to be utilized in future design practice as a pedagogical tool to enhance material and circular economy education. While the network itself will not be implemented in this study, guidance is provided for its future testing and further research. The interviews yield approaches to understand the interplay between processes and materials within circular, sustainable pathways. The strategies connection to the proposed network, allows this research aim to facilitate and promote engagement with sustainability and CE in design, leading to teaching approaches and pedagogical practices. Thereby this work contributes to the ongoing discourse on sustainable design and circularity in the textile industry.