This teaching toolkit for critical materials research is developed for educators in higher design and arts education. It comes out of a 2-year project funded by the NRO Comenius Teaching Fellowship program at the Amsterdam University of Applied Sciences. The project invited a group of design educators and/or researchers to develop ways to help bachelor students explore making practices that center ecosystems rather than human systems. With this toolkit, we share our tried and tested activities, which take bio-based design materials and their unique properties as a point of departure, and offer hands-on activities to critically engage in sustainable material research.