Trailing edge definition

Stupid question. When you guys say for example 3 inches from the trailing edge of the fin do you mean from the back point of the fin. Technically the edge is all along that curve isnt it? 


Here is a preview of the newest twinny. 

Gee that’s the “Death Vader”.   Where did you get that art?  “Trailing Edge”;  1.  The back edge of the foiled fin from tip to base, throughout the entire arc of the foiled fin.   2. For measurement and placement;  The back edge of the fin at the base(where the back bottom edge meets the board.

Haha. I have a very talented friend who wanted to try out a new medium. We did it acrylic on PU and now the question is whether the lamination will stick to it 

Looks cool.   Not my style.  The craziest thing I ever did was a flaming eyeball with purple flames from nose to fins.  A 9’0 Progressive longboard with a hard tail.  Ripped the $#!t out of head high Sewer Peak one weekend.  Not my own shape.  I submitted the design to JG(Jerry Grantham), he shaped it.  Rode like a shortboard.  Lowel

So??  What do you think about my definition???

Seems like a straightforward answer. So basically I am just gonna set the back boxes using the little nub at the end of the futures fin channel more or less. Should be a nice easy way to get it all lined up. I think on my other boards I had been using the point of whatever fin I was going to use on that board and it still turned out fine.