Most efficient fabric ?

[Shewie]

What do you folk reckon is the best combination of materials that will deliver warmth but the smallest pack size possible ?

I'm thinking in a hammock underblanket context.

Would pile and pertex work as well as pertex and down for example ?

Is down the best insulator available for this type of thing ?

[John Fenna]

Down is the greatest I know of - until it gets wet!

[The Cumbrian]

Pile and pertex doesn't pack down very small Rich.

I bought a cheap p & p sleeping bag off ebay a while ago to see what it was like to cannibalise for an under blanket. The bag would barely fit into a 30 litre daysack and was quite heavy. You should, know, you've carried it; it was in my Cronje that day on Ullswater.
I use it now as an emergency bag when I'm taking the Li'l Dude canoeing in winter. Pile sleeping bags have the big advantage of feeling warm straight away, and wicking any dampness away from the skin.

Cheers, Michael.

[Dangerous Dan]

I use a double layer of Thinsulate sandwiched between pertex. I've tried a down equivalent and found it to be only marginally warmer. It does however pack down smaller. The Thinsulate number occupies a 20 litre dry sack whereas the down was around half that. As John F mentioned, you need to keep the down dry where as many synthetics will insulate even when damp. At the end of the day cost and my somewhat twisted sense of ethics pushed me down the synthetic route. I won't push my own opinions here but you may want to research how the down is harvested and make your own decision.

[Toddy]

I can get silk batts intended for quilting. Layer that with a pertex outer and it'll weigh grammes, pack down small and fluff up warm.

cheers,
Toddy

[gsfgaz]

i've got a four season vango sleeping bag with a nackered zip , would that work as an under blanket ...

[Shewie]

At the end of the day cost and my somewhat twisted sense of ethics pushed me down the synthetic route. I won't push my own opinions here but you may want to research how the down is harvested and make your own decision.

No I agree Dan, and the more people who know about it the better I say.

[wentworth]

Down is still the best insulator. Ed Speer's 900 FP down is the best at the moment. I haven't had any problems with down and moisture. I've had water on the ripstop shell and it just runs off. I've gone to bed damp and woken up dry. Since my down gear goes in a drybag lined with a garbage bag, I don't forsee any opportunity for it to become sopping wet.

[rik_uk3]

Down is still the best by far IMHO. You can always pack a large Gortex jacket if you are worried about rain

[EdS]

the best if you could get it s eiderdown - ethically collected from abandoned nests.

[Claudiasboris]

At the end of the day cost and my somewhat twisted sense of ethics pushed me down the synthetic route. I won't push my own opinions here but you may want to research how the down is harvested and make your own decision.

Well said Dan.