Some people like the Slinglight chair…see their website. I have Kifaru Field Chair, 9 oz, and like it a lot…its very compact, you can fit it anywhere in your pack. And I use it even inside my tarptent, for night time reading. Another possiblility, I remember in Colin Fletcher’s books, (The complete walker) he talked about using his walking staff to prop up his e-frame pack, to make a nice backrest. If you could dope out how to do that, maybe with some kind of little socket sewn onto your pack, that would be a minimal weight solution. Or, if you’re using a thermarest, their chair kits are comfy. I’ve tried ’em, still prefer the Kifaru rig. Cheers, Bill