This chapter introduces the reader to the techniques involved in interpreting crystallographic data to build molecular models of protein molecules. It argues that molecular model building is a craft practice. It documents the history of molecular model building techniques and materials, detailing the material culture of protein crystallography. This chapter pays close attention to the three-dimensionality of protein models, and to distinct affordances of different modeling media, from physical models made of ready-to-hand materials, to proprietary software designed to enable smooth manipulation of virtual, computer graphic models on-screen. This chapter argues that it is the tangibility and interactivity of these various media that have enabled modelers to cultivate a kind of haptic and kinesthetic mode of vision in their work of rendering and interpreting molecular structures. This chapter introduces the concept of “haptic creativity” to account for the embodied and improvisational skills model builders rely on in their work.