The atrocious impact of textile and fashion industries on the environment is well known, and with global populations rapidly increasing, this damage is projected to become exponentially hazardous. Addressing this swiftly and effectively is vital to preserve the various ecosystems humans and non-humans inhabit. Biomaterials, especially Mycelium and Bacterial Cellulose (BC), pose viable alternatives to traditional textiles where sustainability is concerned by virtue of their living condition allowing for self-assembly and biodegradability amongst other characteristics. Due to the youth of biodesign as a design field and BC in textile contexts, further knowledge is required, especially considering its interdisciplinary basis. This material-based experimental research was motivated by the desire to address sustainability concerns surrounding the making of fashion from its ecological dimension. Practice-led experimentation targets reassembly within BC’s self-assembling properties, through iterative prototyping. Reassembly experimentations first intended to increase designerly access to fields of scientific backgrounds. Improved material properties demonstrated potential for aesthetic exploration and real-world application. This thesis investigates the essential qualities of BC-knit composites in their re-assembled form. This exploration identifies designeable qualities inherent to BC-knit composites through a material library, whose output is contextualised through spatial situating, and light interaction. Categories represent progressive stages through agency exchange between human and non-human acknowledging the material’s living qualities. Results highlight possibility of designing at several material stages, introducing options to develop ‘growing design’, as well as continue the design cycle post-prototyping, alluding to the act of caring as increasing longevity, and as design tool. Spatial situation and light interactions employ BC’s unique light dispersion properties as broaching new dimensions unachievable through traditional textiles. Nevertheless, despite the improvement in properties and sustainable efforts, the overarching narrative of designing with biomaterials highlights how larger issues, such as overconsumption patterns, may hinder benefits of biodesign as a field within the umbrella of design.