The report is part of the research project "Blue Angel - national ecolabel with international impact". The main objective of this project was to strengthen the use and cooperation of type-I eco-labels within the Global Ecolabelling Network (GEN). Specifically, the project addressed two central methodological challenges faced by ecolabels worldwide. First, the integration of sustainability issues of raw material supply chains into ecolabelling schemes and second, the measurement of ecolabel performance by the determination of quantitative environmental relief potentials.