Set Thickness and Justification in Tool Options palette.
Click on “surface” object and the result is a solid of uniform thickness.
Click on “solid” object and it becomes hollow with a wall thickness of uniform thickness.
Note, the Thicken tool is not a controlled parameter retained with the object. Thus, don't use the Thicken tool twice on the same object, which results in the program trying to hollow out the wall thickness again.
