The growing amount of waste originating from food packaging has increased both practical and scholarly interest in the technological development, design and marketing of sustainable food packaging. This article, in turn, scrutinizes the sustainability of packaging from the consumer perspective, arguing that the sustainability of a package is entangled not only in the content of the packaging but also in the functions it fulfills, and that the conditions for acceptable sustainable food packaging from the consumers' perspective differ from the packaging industry's views. We examine the meanings of the packaging functions for consumers based on the data collected through an online consumer panel in Finland. The findings show that while the containment function of packaging plays the most important role for the consumer in general, the informative function is particularly relevant from the viewpoint of sustainability. Moreover, we identified two novel functions consumers highly appreciate –usability and disposability – that are largely irrelevant from the industry perspective. The findings provide important insights in the transformation to more sustainable food packaging and in the development of novel packaging solutions.