The FairCup is designed for the requirements of prison inmates: Made of plastic, with insulation ribs suitable for hot drinks, and easy to air dry when upside down. A compostable bioplastic based on lignin was chosen as the material. This gives the FairCup a matt surface with marbling. The project was spearheaded by Professor Steffen Ritter, Reutlingen University, and Johannes Schmidt, chief instructor at the Heimsheim correctional facility. Under the guidance of Ritter, a group of 10 students developed the FairCup until it was ready for production. They had the active support of VDWF members ProForm and Bestenlehrer. The FairCup has been injection molded in the workshops of the Heimsheim correctional facility since 2019, and thus serves as a practical example for those inmates training to be machine operators.