In the 1990s, there was a change in capitalist thinking on environmental issues in many global settings, which materialised in what has been termed corporate environmentalism. Beginning with a history of the moulded fibre egg tray and one of its primary manufacturers, this is a case study of how corporate environmentalism came about and was enacted as a confluence of corporate priorities, environmental concerns, production processes, materials, and the development of new measuring tools. Unlike the many environmental history studies that emphasise the role of NGOs and policy developments, this study begins in the business world. More specifically, it is based in the making of environmental knowledge in the form of life cycle assessments and environmental accounts and in the environmental reframing of materials like moulded pulp and plastic. In this way it is the story of how it became reasonable for a manufacturer of egg trays to choose the slogan, ‘Choose Fibre. Save Nature’.