The workshop “Decide your Print” engages high school students outside of classroom settings, with sustainability challenges, focusing on fast fashion’s socio-technical systems. Using collaborative decision-making and systemic analysis, the activity fosters understanding of sustainability’s interrelated dimensions — socio-ecological, technological, political, economic. Combining dialogue, evidence-based education and participatory approaches, it promotes critical thinking and actionable solutions. Conducted at the 2023 Genoa Science Festival in Italy, the workshop aimed to empower participants to propose multi-level strategies, showcasing the potential of informal education to address sustainability through interdisciplinary learning and systemic reasoning.