Multimodal composing using digital media has long emphasized forms of meaning making that extend beyond printed text to include a wider range of available semiotic resources. However, recent research has complicated this notion by highlighting how this availability does not follow inevitably from digital tools but arises from the interplay of their often invisible infrastructures (e.g., hardware, interfaces, algorithms, code). Using data from a technology-rich humanities classroom, the authors explore three frictions that surfaced as students worked within and against these infrastructures to create a collaborative digital story. The authors show how attending to such frictions can open opportunities for inquiry and instruction related to the hidden infrastructures that condition multimodal composing in digital environments. Critical understandings of these infrastructures can support educators in creating more equitable conditions for multimodal literacy learning.