I'm looking at making a quilt, but I'm curious about fill materials. I see a lot on down. But, I was wondering if there is a reason not to mix the synthetic with the down? Maybe a bottom layer of synthetic with a top fill of down, or just a 60/40 mix down/synth. I guess I'm a belt a suspenders guy. It seems it could help with moisture. But, I haven't seen any discussion on this subject and am curious about others opinion and options.

It would help to know if this is for a top or bottom quilt. For bottom, down will let the quilt hug the best... this is important. For top, I really like my Primaloft quilt. Not that down is bad for a top quilt, just that Primaloft gives me the same assurance that you are looking for and, a synthetic quilt is much easier to make. As far as blending the two, I really don't see any benefit to it.

Research the Resist-Down, DownTek and DriDown products...it is down that has a moisture resistant treatment.

I don't know how effective combining types of fill for quilts. I think I saw some type of combination fill at some point when I was looking for a less exspensive option for my underquilt. I ended up buying apex climashield thru thru-hiker.com, resonably lightweight and I should be good down to 30 with the 5oz.