I hope this can be helpful to anyone looking to make a similar project. My first sewing project was to convert a couple of Costco Down Quilts into an underquilt. It worked fine, but then decided I wanted to use the best materials and make something more lightweight and suitable for winter hammocking as well. I knew I needed some type of interior baffles to maintain a good amount of loft. I went with a Karo Step pattern because of the ease of stuffing the down, and the ability to shift it to portions needed most on the quilt.
I designed a quilt using 2 inch baffles in the Karo Step pattern and a differential on the outside
to allow a maximum loft at all times. The quilt averages about 4" of loft when fully expanded. I am
very pleased with the outcome and even though the stitching is not perfect (only my second sewing
project) I have been kept warm and cozy in sub freezing temperatures (down to 25*F but I'm certain
it could go lower), and am super pleased with how it turned out! I would consider this a full size
quilt (70"x55"), a little bit wider than most, but definitely suitable for a double hammock
experience. I'm 5'10" and it gives me full length coverage. Used three different colors of the 1.0
oz HyperD ripstop. Blue for the outer shell, green for the inner shell, and grey for the channels
that house the suspension. I haven't weighed the quilt, but there is a full pound of 800 fill
down in the quilt, plus the fabric, thread, and suspension, I would put it between 24-26oz. I now
have a 4 season underquilt for about half of what it would have cost to buy one retail with
equivalent specs. The suspension system is pretty typical of what you might see on a similar style
retail quilt. The quilt has been dubbed the "Beast Quilt" because of it's serious warmth
capabilities, and the color scheme which is an obvious nod to my favorite NFL team. Go
2 x 1.0 oz HyperD diamond ripstop nylon - Navy Blue / Calendered
2 x 1.0 oz HyperD diamond ripstop nylon - Lime Green / Calendered
1 x 1.0 oz HyperD diamond ripstop nylon - Charcoal Gray / Calendered
1 x Gutermann MARA 70 thread - Lime Green
1 x LineLoc 3
3 x Shock cord - Black / 3/32"
1 x Mini cordlock
1 x 0.67 oz Noseeum Baffle material - 2.5"