Plastic manufacturing is largely based on refining crude oil, and burning plastic waste instead of recycling increases our dependence on fossil fuels and the use of virgin resources. In addition, plastic waste and the microplastics from its slow degradation have a wide range of negative impacts on ecosystems. More sustainable alternatives to the current use of plastics are needed. In a sustainable circular economy, plastic waste is recovered as a material and the effective recyclability and material recovery of plastic, or plastic-containing products is mainstreamed in Finland and globally. The shift towards a sustainable circular economy requires not only technological solutions but also new value networks, logistical solutions, and investments in the collection of plastic waste and the production of recycled plastic raw material. Identifying business opportunities and investing in the circular economy of plastics requires a comprehensive and sufficiently accurate overview of the different plastic streams and their suitability for different recycling technologies in Finland. The STAR project responds to this information need by producing a unique plastic flow model for Finland, covering both quantitative and qualitative dimensions.