Interface and General Tasks > Manage view windows > 
Make certain windows stay in front or behind others
 
 
 

How to change window depth settings so certain windows are always in front of or behind others.

Make a window stay in front or behind other windows

  1. Click the depth icon in the window’s title bar.

  2. Type number between 1 and 9. The window will always be in front of windows with a higher number, and behind windows with a lower number.