Against the backdrop of the expansion of the literacy curriculum to include multiliteracies in education systems around the world, we discuss how a design-based research approach can contribute to practical outcomes in building the participating teachers' confidence and competence in their pedagogical practices, developing scalable lesson resources for other teachers to use and adapt, and distilling design principles that can inform the teaching of multiliteracies across contexts. In this paper, we introduce the research project we have implemented based on a design-based research (DBR) approach and describe the features of the project in relation to the characteristics of DBR. We highlight the focus in DBR to improve practice and discuss how the classroom practices of the participating teachers have improved. We also draw on the perceptions of the teachers from the interviews and reflections they have made and suggest that they have grown professionally in their confidence. Through the co-design sessions between the researchers and teachers, we have distilled design principles, that is the learning processes for the teaching and learning of multiliteracies. These learning processes are applied to guide the design of the lesson packages as resources for teachers. While it is well-recognized that teachers are critical in the implementation of curricular reforms, we are interested to understand how researchers and teachers can work together through a design-based research approach to fully implement the curricular reforms.