It's pretty simple. If you were to draw an outline of your frame perimeter, then you would draw another profile around it offset 20" from your frame. If you had a square frame, the corners of this outer profile would be rounded with a 20" radius. You may fill up this entire outer profile with extensions if you want, but you can't go past it.
For example:
__________________
Design/fab team 2011-2013
Design/fab mentor 2014--
There are three types of people in the world:
1. Those who make things happen
2. Those who watch things happen
3. Those who wonder what happened.
