Compression-based haptic feedback has been used in wearables to issue notifications, provide therapeutic effects, and create immersive storytelling environments. Such worn devices are well studied on the wrists, arms, and head, however, many unconventional yet context-rich areas of the body remain underexplored. Current haptic prototyping techniques have large instrumentation costs, requiring the design of bespoke embedded devices that do not have the flexibility to be applied to other body sites. In this work, we introduce an open-source prototyping toolkit for designing, fabricating, and programming wearable compression-based interfaces, or compressables. Our approach uses a lost-PVA technique for making custom inflatable silicone bladders, an off-the-shelf pneumatics controller, and a mobile app to explore and tune haptic interactions through sketch gestures. We validate the toolkit’s open-endedness through a user study and heuristic evaluation. We use exemplar artifacts to annotate the design space of compressables and discuss opportunities to further expand haptic expression on the body.