This paper explores the ways in which multimodal classroom discourse could inform a social justice agenda through broadening the base for representation in the classroom. It identifies some of the challenges and opportunities of designing multimodal classrooms in diverse and developing contexts, where there are vast differentials in terms of access to resources. It focuses on the ways in which multimodal classrooms could recognise a range of student resources, whilst at the same time enabling access to dominant forms. This includes access to the discourses and knowledges of official curricula and formal methods of assessment, as well as the creation of dispositions towards meaning-making outside of the classroom. Formal education often closes down access to a range of semiotic resources and multimodal classrooms can potentially recover "recognition" of these. This paper explores ways of designing multimodal classrooms for social justice in order to bring to the surface the range of students' resources which are often not noticed or valued in formal educational settings. It proposes the following: the questioning of boundaries between domains, harnessing students' representational resources, developing metalanguages for reflection and creating less regulated classroom spaces.