• Composing process focus including screen recording and think aloud protocols. • 11 explicit composing process activities are defined and described. • Establishes explicit metalanguage for digital multimodal composing teaching & research. • Includes illustrations of complexity of multimodal composing. Daily writing practices occur in digital environments and are often multimodal. Studies have attempted to interpret composing processes in these environments through text-based lenses and findings have yet to explicitly or effectively define and illustrate the complexities. This case study explores processes and activities of 5th-grade students as they compose using digital tools, multimodal resources, and navigate the opportunities those tools and resources afford. Findings suggest 11 process activities; three unique to digital multimodal environments, and all having influences of the digital and multimodal environments in which composing takes place. Results 1) demonstrate the potential to develop a specific metalanguage for digital multimodal composing, 2) begin to inform a specific digital lens for interpreting composing in these 21 st century environments and 3) help practitioners design instruction that best support student composers in classroom contexts.