The medical record is a central artifact used to organize, communicate and coordinate information related to patient care. Despite recent deployments of electronic health records (EHR), paper medical records are still widely used because of the affordances of paper. Although a number of approaches explored the integration of paper and digital technology, there are still a wide range of open issues in the design of technologies that integrate digital and paper-based medical records. This paper studies the use of one such novel technology, called the Hybrid Patient Record (HyPR), that is designed to digitally augment a paper medical record. We report on two studies: a field study in which we describe the benefits and challenges of using a combination of electronic and paper-based medical records in a large university hospital and a deployment study in which we analyze how 8 clinicians used the HyPR in a medical simulation. Based on these empirical studies, this paper introduces and discusses the concept of collaborative affordances, which describes a set of properties of the medical record that foster collaborative collocated work.