We investigate reverging - the phase between the diverging and converging steps in a creative process - in the context of a visual thinking agency. Creative facilitation literature advocates for such a phase, aimed at revisiting and rearranging ideas generated during diverging, to prepare for converging. However, in practice this step is often neglected or not performed well, resulting into a sense of increased complexity or lack of client ownership. Two studies were used to investigate reverging in context: a preliminary study consisted of interviews and observations to better understand reverging in current visual thinking practices. The follow-up study focused on co-creating a tool to solve the problem identified in the preliminary study. While the preliminary study revealed the need to involve clients in both diverging and reverging phases, the follow-up study resulted in the creation of the Whiteboard Canvas. The tool was tested in practice and several benefits of reverging in visual thinking practices emerged. The tool empowers visual thinking practitioners to involve their clients more actively in reverging, resulting into a more deliberate creative process and an increased sense of client ownership.