The MATTER project aims to evaluate the recycling of mixed (post-consumer) plastic waste streams and to use the generated data to develop a decision supporting framework. Technical and market-based criteria will be developed to support an optimal plastic waste management system. More specifically, the project will focus on the P+ fraction of the extended P+MD collection and recycling scheme. Partners from across the whole value chain are included in the project consortium: separation and pretreatment (Indaver and Bulk.ID), mechanical recycling (Borealis and ECO-oh!) and thermochemical recycling (Indaver and Borealis). Organizations such Fost Plus, Plarebel and OVAM will be closely involved in the project execution.