Purpose – Eliminating overpackaging is a central question in sustainable development, and poses a dilemma for retailers. Since packaging is a differentiation tool for private labels, eliminating it could limit the capacity to give those labels an equivalent image to national brands just as much as it could be a sustainable development opportunity and a positioning instrument. Drawing on the attribution theory framework, this article examines how eliminating overpackaging influences consumers’ perception of products sold under generic and mimic private labels, and their purchase intention. Methodology – This research uses a 2 (overpackaging: present vs. absent) x 2 (brand concept: generic vs. mimic private label) between-subjects experiment on a convenience sample of 217 French consumers. The conceptual framework was tested using ANCOVA and mediation analyses. Findings – Our experiment shows that eliminating overpackaging does have an influence on mimic private labels’ image, particularly on perceived quality, convenience and environmental friendliness. We also find that this influence negatively transfers to purchase intention for mimic private labels through lower perceived quality and convenience. No such effect appears for generic private labels’ image. Value – This study addresses an issue as yet unexplored in marketing – the effect of overpackaging on private label products – and proposes areas for managerial and societal reflection relevant to retail chains interested in eliminating overpackaging.