Maybe I'm being redundant, but has anyone thought of or posted the concept of a sleeping bag system? I'm thinking along the lines of how I dress and even cover my hands: silk or light wool (if they make it) liner, a fleece sleeping bag, a lightweight regular sleeping bag, and maybe even a silnylon overbag. Polypro makes me sweat and itch so I prefer the natural materials. Then again, maybe with clothes on, some of this in unnecessary. Any experience?

Being this IS BackpackingLight, I think pretty much everyone here is either already doing this , or in process of doing this.

Personally, I'm pretty much in process. I'll be trying my Cocoon Pants & Montbell U.L. Down Inner Parka to see how low they'll work with my custom Nunatak Ghost and how low they'll comfortably work with my WM Ultralite.

You are definitely on the right track though...

Im just kidding, but say its a fifteen/twenty degree night. What I would do is have an insulating pad (of course, not going to sleep on rocks), a thirty degree bag, a silk liner (i.e. jagbag)(adds about ten degrees), and then some clothes like gloves and long johns, maybe with a pinch of down jacket in the mix if there is an extra dash of cold in the batch.

Unless you are talking about four season, winter camping. Then of course it's layer up time, maybe with fleece.

edited to say this:

sleeping systems rock my cozy socks

Edited by benjammin21 on 12/26/2007 18:50:30 MST.

Definitely on the right track in terms of thinking of your "sleep system." One of the tenets of most BPLers is to think not of individual pieces of gear but the total performance of the interacting system.

But . . . fleece is insanely heavy for the loft it provides in a situation like sleeping where you don't need it's greater breathability and resistance to crushing under pack straps. That weight is much better spent on high-loft insulating fill, synthetic or down, either in clothing (puffy pants, jacket) or in the sleeping bag. A standard practice is to get high-loft pants and jacket for warmth around camp, and use them to boost the warmth of your sleep system (so you can carry a lighter bag).

And silnylon doesn't breathe at all, so you'd be trapping all your insensible perspiration in the overbag, rapidly reducing your sleep system to a soggy mess. Not recommended. A breathable bivy with a top made of Pertex Quantum or Momentum 90 on the other hand can help keep off stray moisture and reduce convection, particularly if you use a quilt (another common strategy around here to maximize warmth / weight ratio).

There are some good articles on this site on this topic, but they're mostly member-only. If you're serious about it, though, the membership fee gets you discounts in the shop as well.

Michael, that is an astute observation, especially if you did not already read about it here. Improving the performance(while reducing the weight) of outdoor gear is like improving a system of systems, of which the sleep system is one. It has requirements for wind protection, water repellency, vapor management, conductive and radiative insulation, etc... and of course a combination of durability and yet low weight. My system is comprised of a ground sheet, tent, sleeping mat, bivy sack, sleeping bag, and the layer(s) I wear to bed. The sleeping bag is only a small and light part of the total system; in fact I could probably do without the 1 lb bag at all in a pinch.
I suggest you read the forums for more info..

Thanks all. I am pretty serious about this: I'm trying to convince my 15 y/o son to go winter camping. The six y/o is all gung-ho, though, and I could never get the other two to leave their warm beds. So my thinking is this: I have a 25 deg bag (which is pretty lightweight). Add a silk liner, which I would carry all of the time, and in the winter, dress in hi-loft down pants and top. Next to my skin: silk, wool, silk/wool combo, or bamboo underwear. Next, fleece top and pants. Then the down.
For 3-seasons, ditch the down. I'm looking for grey t-shirts which I can then wear any time of year.