|Select > Shrink … command shrinks the selected poly-faces/poly-vertices by the specified depth. Before executing this command, there should have some poly-faces/poly-vertices selected already. If not, this command is disabled.|
How to use Shrink command
|Select Select> Shrinkin the menu or click the icon in the toolbar.
You can also shrink poly-faces one depth by selecting it from RMBpop up menu in the view.
|Change Depthto 1.|