Informal science education programs are often designed to engage youth in scientific practices in a fun, interactive manner that supports development of science identities, often through the inclusion of opportunities to engage with science communication practices. This study examines youth engagement with science communication practices in one informal physics program over the course of two semesters. In this program, youth participants perform experiments alongside adult mentors and document their experiences in science notebooks. We find that shifting the format of the notebook pages away from school-like lines and towards more flexibility of style of communication with a greater emphasis on learning new science vocabulary impacts how often youth engage with communication in the program as well as how they explain, discuss, and express their scientific findings. These results suggest that providing more flexible formatting for science communication may facilitate engagement and opportunities for science identity development among youth participants.