Here's some pics of my IX underquilt. Today I finished it up by adding two draft collars. The photos show a trial fit to my Hennessy Explorer hammock. I think I need to dial in the head end a bit but the foot end seems to seal up fairly well.
I'm 5" 11" and the foot end of the UQ lays under the middle of the calf of my legs on a diagonal lay. In the fetal position (I sleep this way a lot) I can get completely inside the UQ.
IX underquilt with 3 layers of Insultex
Close up of head end showing draft collar and a grosgrain loop I added in case I need to do something at the middle of the head or foot ends.
The rest show the head or foot ends in various sleeping postions.