In the 
CAM tree, right-click 
Turning Stock and click Transparency.
The Stock Transparency dialog box adjusts the transparency of the stock as it is drawn in the graphics area.
To change the stock transparency:
In the CAM tree, right-click Turning Stock and click Transparency.
Low - The left end of the slider minimizes the transparency of the stock so that it appears more opaque.
High - The right end of the slider maximizes the transparency of the stock so that it appears more see-through.