AutoCAD 2008 User's Guide > Control the Drawing Views > Change Views > Shade a Model and Use Edge Effects > Customize a Visual Style > Shade and Color Faces > 
Shade and Color Faces
Concept Procedure Quick Reference
 
 
 

To make all faces in a viewport transparent

  1. Click Tools menu Palettes Dashboard.
  2. In the Visual Style control panel, click X-ray Mode.