For the inside of an emergency sleeping bag, mostly the foot area
Having a discussion about UL sleeping gear and the subject of sleeping.bivvying in your boots was mentioned.
I have thought about what I keep in my ski touring day pack and realise that the UL Brooks Range half bag I use would not survive a night with my wearing my Telemark touring boots. In a wet and soggy survival situation I am not going to be taking my boots off as they are simply too warm not to use and they are much warmer with the shells on and unbuckled. I only need to survive a night at -10C as it doesn’t often get much colder than that. So I am thinking on making a new half bag with a reinforced foot area big enough to take my size 11 Telemark boots [ which are 336mm long and 129mm wide] so my query is regarding the most suitable LW fabric and what inside length I can get away with as a minimum to avoid buying too much.
I need to minimise my spend on this project so while not the best insulation I happen have some 3M Lite-loft which I need to use if I can’ find enough APEX here. For the rest of the bag inside and out I’m hoping can use what old nylon taffeta I have, the extra few grams won’t make any difference in real terms