Inequitable access to science, technology, engineering, arts and mathematics (STEAM) has been explored by multiple studies which have shown that some publics are underserved by existing informal educational and cultural provision, and under-represented in related study choices and careers. Informal science learning (ISL) and public engagement with research activities (such as science festivals) tend to attract audiences which are largely white, middle class and already engaged with STEM (science, technology, engineering and mathematics). This article describes the development of an engagement approach and model through a story-based festival (SMASHfestUK) which was specifically designed to attract new and diverse audiences, including Black and mixed-heritage families, and families living with socio-economic disadvantage. The festival was delivered on five annual occasions, each co-designed with a wide selection of stakeholders, including audiences, researchers, performers, institutions and organizations, and considered as an iterative prototype
