Blended Reality Space is our term for an interactive mixed-reality environment where the physical and the virtual are intimately combined in the service of interaction goals and communication environments aimed at health support and rehabilitation. The present study examines the effect on rated presence and self-presence of three key factors in the way blended realities may be implemented for these purposes. Our findings emphasize the importance of tangibility for presence, but suggest that presence and self-presence are unrelated phenomena. These findings will be incorporated into design principles for our planned work to develop free movement-based interactions for motor rehabilitation as well as blended-reality spaces for collaboration between hospitals, care organizations, and the home.