Blender has lacked a simple hollowing/shelling tool for a long time. If you wanted to make a hollow version of an object, your only option was to export it into another program and then re-import a hollowed version. This is a laborious process which is destructive to the model pipeline, which would need to be repeated whenever a change is made to the model.

This tool is designed to provide a non-destructive hollowing step that can be easily combined with existing workflows. It is ideal for those who design for 3d printing and especially those who design for online printing services, where you have little control over part thickness.

This tool allows you to select different output geometry, including the hollow mesh only and hollow + original mesh.

It allows for differing levels of geometry detail, allowing for fast rough versions for visualisation and higher level versions for final versions.

It has a simple (fast) and complex (slower) solving methods. The 'Complex' method is more tolerant of non-manifold geometry, such as holes and flipped normals.

Also included is the ability to alter the Hollow thickness based on various properties, such as proximity to another mesh. This can be used in interesting ways, such as generating surface textures or patterns of reinforcement.