In recent years, the environmental problems associated with plastics have become a matter of global concern. Current responses seek to replace plastics with other materials, however it is not yet clear that these alternatives will deliver improved environmental outcomes. There remains an urgent need for more nuanced understandings of plastics, their role in society, and their environmental impacts. Drawing on social science perspectives that emphasise the co-evolution of materials and society, this paper outlines a socio-technical approach to plastics and social change. In this view, plastics are understood in terms of the networks and relations of which they are part – highlighting the limitations of both technological solutions and the blanket condemnation of particular materials. The analysis focuses specifically on plastic packaging, exploring the interplay of technological innovation and consumer practices to better account for processes of change. Our arguments are advanced through reference to three case studies: the launch of a ‘roast in the bag’ chicken by a food retailer, the switch to compostable packaging by a potato crisps (chips) brand, and the refilling of plastic bottles by a cosmetics company. Particular attention is paid to the relationships between commercial, environmental and regulatory concerns. To conclude, we consider implications of the approach presented here for transdisciplinary and policy debates about the problems associated with single-use plastics.