Many commentators recognise the need to make clothing more sustainable due to its deleterious environmental and social ramifications. However, it is challenging to change the consumer behaviour that drives fast fashion markets because people have complex relationships with clothing. In this study, we illustrate how the relationships that people have with clothing can be shaped by workshops that immerse them in making, mending, and modifying garments. Such experiential learning can encourage adoption of more sustainable clothing choices, such as reducing consumption of new garments and prolonging the life of already owned items of clothing. We present findings on a strand of work from the Arts and Humanities Research Council funded S4S: Designing a Sensibility for Sustainable Clothing project, which explored the affective economy around clothing, and considered how emotive affects around garments operate as a conduit to self-sustain particular practices. Our significant contribution brings political analysis firmly into the debate about sustainable clothing by merging literatures on behaviour change and affect, through exploration of a novel longitudinal (9-months) qualitative data set. At the start of the project, participants generally thought of clothes as being low-cost (and therefore disposable) items. The workshops, in contrast, presented garments and the materials from which they are made as precious, complex and fluid – in a process of continual possibility. For pro-environmental behavioural change, we find that immersion in the materiality of clothing mobilised affective processes, enabling potentially transformative affective encounters. Further, we found that group learning environments need to do more than simply teach approved normative values and behaviours. Pro-environmental behaviour change initiatives need to provide people with the space to create and situate their own knowledges, enabling affect to be mobilised, activated and supported by appropriate cultural milieu.