InsertSolidShell
The Shell command enables you to create a shell from a closed solid, or a solid with parametric thickness from an open solid (a solid created from the surfaces that bound it by using the InsertSolidMake Solid command).
When creating the shell from a closed solid, you can select one or more faces to be removed and also specify different thicknesses for selected faces.
When the command is applied to open solids, the resulting solids are manifold even when the offset surfaces deriving from two adjacent edges generate two vertices instead of one.