A variety of brands and companies are marketing their approach to sustainable practices and the meaning of the term ‘sustainability’ has become blurred and inconsistent. The researcher and designers Miriam Josi and Stella Lee Prowse are proposing an alternative discourse and practice to this tendency. Here they explain their work for their studio Aléa and suggest how research practices and experimentation in material production can be a response to the current fashionability of discourses about sustainability. Interview by Marco Pecorari.