Printing simple electronic circuits, sensors, and wiring on paper is already being used for the production of smart labels and intelligent packaging, among other things. However, paper—as a bio-based and easily recyclable material—can also be used as a functional material for the production of multilayer printed circuit boards. Therefore, additional requirements must be met and reliability issues resolved in order to develop a competitive technology. The EU-funded CircEl-Paper project is dedicated to researching and optimizing materials and process technologies for paper-based printed circuit boards, paving the way for green electronics and contributing to the establishment of a circular economy for the increasing amount of electronic waste.