You can construct thin region features with or without capping faces. A capping face can be a face or construction surface that defines how you want to cap the thinned region.

You can use a capping face with or without an offset. When you specify a capping face with no offset, the face is extended to cap the bottom of the thin region.

When you specify a capping face with an offset, the bottom face is offset a defined distance to cap the bottom of the thin region.