I have some LW ripstop fabric and some insulation from a couple of sleeping bag salvages. I have a mind to make myself a better little synthetic bivvy sleeping bag along the lines of the Patagonia Hybrid but with the addition of a silnylon cowl. I am having a hard time getting around the design of the cowl part. PHD in England are the only people making a cowled sleeping bag that I could find and from the single picture on the website I cannot fathom how to do it.
https://www.patagonia.com/product/hybrid-sleeping-bag-regular/70070.html
https://www.phdesigns.co.uk/zeta-synthetic-primaloft-overbag
Has anybody here done it and could give me a few pointers?






