This document, the main report for the Plastic Supply Chain project carried out for the Netherlands Institute for Sustainable Packaging (KIDV), describes two interventions for further closure of the plastic packaging chain, in terms of both resources and economics: ‘Optimisation of current systems’ and ‘Addition of new systems’. CE Delft was commissioned by KIDV to qualitatively assess the direct and indirect environmental impacts, both positive and negative, of both interventions.