This paper presents SketchSpace, a system that allows designers to interactively sketch  device’s interactive behaviors by imbuing digital functionality to passive materials. SketchSpace requires no augmentation of the device itself, but instead it uses a depth-sensing Kinect camera to simulate the use of hardware sensors by using depth information to infer an object’s threedimensional position, motion, proximity, shape, deformations, and touch events on its surface. A designer can map these inputs to desktop applications in real-time and thus experiment with different interactions. We showcase how SketchSpace can be used to prototype two devices: from tilt sensitive mice to bendable displays. In general, we discuss how this simplifies the process of generating an interactive device sketch and supports rapid exploration of design solutions.