I don't think I have seen anyone do this and it was really simple, materials are readily available, and both are tested overnight.
The winter underquilt got down to the low teens. It weighs 2lbs 11oz with the stuff sack.
The summer underquilt got down to 39 degrees. It weighs 2lbs 4oz with the stuff sack.
All materials are available at your local walmart, except the sol emergency blanket.
Be warned: I have never sewn anything before in my life. I have only ever used a sewing machine twice to make these underquilts. And, I did this tutorial via a video and I have never really done any videos before. Yes, three ingredians to catastrophy!
The video is below (sorry if this is not an acceptable method, just easier for me to explain .... basically (inside joke, you will see why).