In this breakout, we present a unique collaborative evaluation project where the University of Sussex Library and Bloomsbury joined forces to explore and assess the library’s publishing practices. This partnership, where colleagues from Bloomsbury’s Open Research, Textbook Editorial, and Metadata teams delved into the operations of an open textbook pilot publication, was an opportunity for meaningful knowledge exchange and honest dialogue about strengths, weaknesses and the path ahead. In this session we’ll highlight how we approached the collaboration, outline the valuable discussion points and recommendations that came out of the project, and reflect on the value of the critical friend.