This paper discusses the domain of do-it-yourself (DIY) biomaterials applied to design, by analysing aims, speculative value and aesthetics emerging from this encounter. From a transdisciplinary perspective, the convergence of postanthropocentric philosophies with systematic experiments in two different laboratories, located in Italy and China, demonstrates how design practices can contribute to new forms of human–nature relationships, highlighting a pluriverse way to understand life. Because of the dual approach of philosophical theories and hands-on experiments, biomaterials become tangible tools which change the very idea of “designed objects”: they assign to artefacts circular, living, and integrated properties, thereby placing them within the notion of an ecosystem. Nevertheless, beyond bio-based properties, the three most interesting qualities emerging from this theoretical–practical study are (1) 1:1 scale of production, (2) organic-formless aesthetic, and (3) multispecies coexistence. We argue that through such a model of bioproduction, the designer can assume the role of catalyst for a postanthropocentric vision, dismantling the feeling of separation, alterity, and not-belonging between the human and the nonhuman, between objects and organisms.