See next step...........
Step 1: Underquilt Assembly
This winter I was camping in the nearby woods and during the night there was a wave of 2C degrees wind. It was suddenly very cold in my hammock! Luckily I had an extra fleece jacket within my wardrobe. Still, it was one quite unpleasant experience.
Well, my bridge hammock must get additional layer of thermal protection for such events. And, as you can see from pictures, I made it from military surplus canvass (air and water tight, cheap) + artificial wool insulation + aluminum blankets-hiking pad from Ebay.
All together, this underquilt now has a thickness of about 30-32 mm. Total weight is 1300 grams, and I reckon this thermal protection to be equal to at least 10 cm thick quilt if it were made from only two layers of canvass and insulating artifical wool.
But let us wait till the end of year, the first snow and wintry temperatures for the final evaluation!