In this paper we explore the use of in situ occlusion resolution in mixed physical/digital tabletop scenarios. We propose the extension of back-projected tabletops with interactive top-projection to turn the physical object’s surface into peripheral displays. These displays are used to resolve occlusion in situ without the need to use additional tabletop display space and keeping the spatial perception of the occluded objects. We contribute a visualization concept and a set of interaction techniques for in situ occlusion resolution and easy access to occluded objects. The techniques are implemented in a system named ProjecTop, which is evaluated in an quantitative user study. The study results highlight how top-projection can be beneficially used. We conclude with a set of design implications derived from the study’s results.