This paper reports on the co-design experience of an educational guide experienced by its author. The case is that of the primary and secondary networked classrooms, back to 2010. It was based on ten years of research conducted by a multicenter team, in collaboration with many stakeholders from several school boards. In addition to the process of collective development of the resource itself, we retrace its historical roots and discuss the issues and benefits associated with the process implemented. Aware that the reported practice cannot be reproduced as it is, we believe its sharing could nevertheless guide researchers interested in the co-design of pedagogical artefacts with practitioners.