Today I took my old (about 15 yrs old) synthetic sleeping bag and cut it down to size, ripped off the zippers, and finally ripped out the old insulation. For fun I stuffed part of it tonight with down that I got from a comforter off craigslist for $10. That comforter will likely fill 3/4 of it. My aunt said she thinks she has a down comforter that she can send me for free! so looks like my under quilt will be rather cheap! hoping it works well when it's finished! the part I stuffed tonight has about a 3" loft... I might stuff it a bit more than that though. I'll update this when I finish it up... just had to share my progress for today because I'm super excited!