The use of open textbooks in universities is according to some organisations changing the higher education landscape and is promising for the mainstream adoption of OER. The aim of this paper is to analyse authors' views of agency and empowerment when they plan, create and reflect on their open textbooks, their teaching and students' learning. Another aim is to analyse the ways in which knowledge supports authors' creation of open textbooks and tensions inherent in this practice. This qualitative study used a modified version of a validated questionnaire for 1 h long semi-structured interviews with four interviewees, conducted over 4 days. The data from the interviews were analysed in three steps combining two coding structures, for self-regulated learning and levels of contradictions. The results suggest that the four authors engendered a sense of relational agency in the creation process. They indicated that they valued openness and the pedagogical project itself by highlighting both teachers' and learners' perception of agency and empowerment. The data also support the authors' concerns about the disruptive nature of open textbooks regarding stability versus adaptation and data ownership as it relates to use of learning analytics and commercial interests, indicating considerable contradictions in open textbook practices.