This paper addresses the problem of organizing material in mixed digital and physical environments. It presents empirical examples of how people use collectional artefacts and organize physical material such as paper, samples, models, mock-ups, plans, etc. in the real world. Based on this material, we propose concepts for collectional actions and meta-data actions, and present prototypes combining principles from augmented reality and hypermedia to support organising and managing mixtures of digital and physical materials. The prototype of the tagging system is running on digital desks and walls utilizing RFID tags and tag-readers. It allows users to tag important physical materials, and have these tracked by antennas that may become pervasive in our work environments. We work with three categories of tags: simple object tags, collectional tags, and tooltags invoking operations such as grouping and linking of physical material. Our primary application domain is architecture and design...