The sustainability of materials used in Participatory Design processes-be they tangibles, or other-typically provided by the designer; is not commonly foregrounded. We focus on the social and environmental impact of tangibles by considering two cases. The first concerns the conception of a Forest-Library. A steering committee gathered to map stakeholders across a municipality, using foraged elements from a barn. The second case brings together organisations concerned with waste activism, to collectively compare and negotiate their stakeholder interrelations. The foraged tangibles are environmentally sustainable by virtue of a) being foraged rather than designed, and b) their ability to be returned to use or to the nutrition cycle once their usefulness to the PD process has ended. Following Liboiron's conceptualisation of pollution as colonialism we consider if their connection to place might assist in troubling the ways that these mapping processes might be considered socially, as well as environmentally sustainable.