The fourth issue of Fashion Highlight proposes a planetary perspective on fibre, viewing it as a dynamic interplay of material flows and forces shaped by both human and non-human actors, the living and the technological, and the crowded continuum between them. The papers for this issue 'Fashion’s Fibres as Planetary Flows’ write about the pivotal role of fibre in a circular economy, the governance of fibre, the ethics of fibre, the cultural histories of new and old fibre technologies, fibre and place, and provocations on fibre’s agency and materiality.