To Cosmetically Shade a Model
To apply temporary shading to an image click View > Model Display > Temporary Shade. This procedure applies temporary shading without affecting the saved view of the model and without canceling the view choice for the current session.
The shading is removed when you repaint the view.
Do not use this procedure to shade the model view permanently (so that it remains shaded even when reoriented). Instead, on the View tab, click the arrow next to Display Style and click Shading.