Thicken works on all faces of the model and does an offset at each vertex and connects the resulting solid.  It does the equivalent of an offset or inset of the body.  The first image below shows the original body, the second image shows an offset and the third image shows an inset.  If you thicken an object with a constrained face, the constraint will be maintained with an offset on the resulting thickened faces.  See the bottom two images for an example of thicken with constraints.

Normal Push

Normal Push copies and then moves the selected faces out along the normal defined at each vertex by the average face normal at that vertex.  The first image below shows the selected faces and the second images shows a normal push.

Flip All Faces Flip Faces flips the normal of all of the faces of the mesh or just the selected faces.  Below shows an example of Flip Faces.

Created with the Personal Edition of HelpNDoc: Easily create EPub books