A growing number of Open Science Partnerships (OSPs) have emerged around the world. These are precompetitive public-private research partnerships that adhere to principles of open science, which includes putting the research outputs into the public domain and precluding participants from seeking Intellectual Property (IP) rights protection on these outputs. Despite the growing interest in OSPs, they have been the subject of limited scholarly attention. To remedy this situation, we examine the similarities and differences of OSPs. Based on a comparative, qualitative study of five OSPs in biomedicine, we propose two crucial dimensions in OSP design - research aims of the partnership and degree of industry orientation - as the basis for four archetypes of OSPs. These archetypes are intended to provide a starting point for further research and for practitioners wishing to ensure that means applied match the desired ends that motivated the OSP.