The rise of digital resources has had profound effects on mathematics curricula and there has been a concurrent increase in teachers flipping their instruction--that is, assigning instructional videos or multimedia for students to watch as homework and completing problem or exercise sets in class rather than vice versa. These changes have created a need to better understand not only the features and learning affordances of these videos but also the phenomena of instructional videos taking the place of textbooks altogether. Drawing on an enacted mathematics curriculum framework, this article reports on a study of a mathematics teacher who implemented flipped instruction and created her own instructional videos and multimedia resources as replacements of printed textbooks. We examined the relationship between the teacher's printed textbook and the digital curriculum materials she used with her flipped mathematics classroom. We also explored her role in creating the digital curriculum materials and the ways in which those materials were used in-class. The case reveals similarities between the new material design and conventional textbooks and it also illustrates the teacher's simultaneous work designing and enacting digital curriculum materials. The broad issue of considering videos as curriculum materials rather than only as instructional representations is discussed.