Best material for UL blanket? Anyone have any?

This is a tough one, a really comfortable fabric that is warm, lightweight, and semi-wind proof. Micro fleece isn't particularly wind proof–it's slightly better than regular fleece but still fairly breathable.

There are some lightweight, very tight weaved microfiber polyester fabric out there that might be suitable (Pertex makes a couple). In some ways polyester has a different feel than nylon, and that people tend to find polyester a little more comfortable whereas nylon can feel a bit clammy especially when you're talking very tight weaved and smooth, flat stuff. Nylon can be made to be more comfortable as in the supplex and taslans for example, but these are usually heavier.

Polyester will be a bit heavier than the super light weight nylons though, and a bit less durable. It may be very slightly warmer than the nylon. If you're going for ultimate comfort, what i might do in your situation is either take a light weight, very tightly woven synthetic fabric (either nylon or polyester) and sew some very lightweight silk to one side of it. The silk will be more comfortable against the skin, and with two thin layers you will be trapping a bit more air so you're increasing the warmth a bit too. Silks can get quite lightweight. Something like a 5 to 6 momme should work well i think. Silk is surprisingly strong for a natural fiber/fabric, though you won't to be rough at all with such thin, lightweight stuff.

Steven,
I think a tightly woven silk is as "wind resistant" as nylon or poly, so it might just do the trick. The typical silk used in liners like Sea to Summit is quite densely woven, so you might want to give that a test. I don't think it's "wind proof", but I believe it might be enough for your purposes.

Try merino wool, a good size blanket will weigh about 400g, http://www.extremtextil.de have some in variuos weights.
Also, if you can afford it, pashmina wool is the best warmth for weight ratio. I travelled around India and SE Asia for two years with a silk bag, and a large pashmina and slept fine.
Cheers,
Fred

Awesome tips! Thanks. I want to check out some silk. I'm not sure how I'll like the feel of it.

So something like Quantum at 0.9oz with 1oz silk might be better than just silk?

I did find a Cocoon egyptian cotton mummy liner at 7.4oz but I wonder how thin it is.

Hi Steven,

I've experimented with different silks, and different synthetics. The problem with silk, it's hard to find a super tight weaved version of it that will be more truly windproof, whereas if one buys some Quantum or M50, or what not, you know it's going to be quite wind-resistant to near windproof. I've yet to see a silk fabric that is as wind resistant as these super tight weaved synthetics. This is one of the reasons why silk is not used as a liner for Down sleeping bags or quilts, because most silk fabric is going to let out feathers (especially) and some down.

So yes, that's personally what i would do, is to put a layer of silk together with a very light weight and tight weaved synthetic and put the silk side on the skin. It will be a bit warmer with two layers since more air is trapped. Silk btw, is a somewhat unusually warm fabric for the weight and this is because it's often very fine fibers which are triangular shaped and protein based. The combination of this, makes it warm for it's weight and thinness though it's not a miracle fabric by any means. Fine/high quality silk is actually warmer than Merino on a weight to weight and thickness basis, i think.

It would be much heavier, but you could also look into "raw silk", which is almost more like a woolen fabric, much thicker and heavier, but quite warm. It's less durable than woven silk though. I'm not sure how wind resistant it is, i have some and will do some breath tests and get back to you. A truly wind resistant fabric is somewhat hard to suck air through.

I checked out the Cocoon silk liner and it doesn't seem like enough. I'm wondering if very thin silk with M90 (M50 says low breathability– that could make things clammy) will be enough warmth but all I can do is try it out.

Does anyone have a good source for silk? It doesn't seem like internet retailers list the momme.

http://www.thaisilks.com/

I think even some of our Austrailian friends have purchased here.

I generally look for the thinnest white silk available.

–B.G.–

If you're going the nylon route, use Nobul 1. It is silky soft and will be much lighter.
I have an M90 bivy that I've used inside my bag and condensation was an issue.

Although the Nobul won't help to much with wind, so maybe the best idea would be an M50 (or Nobul 2 would be even better) on top with silk on the bottom.

There is also argon which is softer than all but the Nobul 1.
Its wind resistance will be a little better, but I think the Nobul 2/ silk would be the way to go.
You could do this with less than 2.5 ounces of material if you find some nice light weight silk.

The silk bottom will also breath better and you won't have any condensation issues.

With such a light quilt, you do not want to add the 4.5- 5 ounces it would take for an M90 combined with silk.

I would tapper the NB2 from 30" at the foot to 40" at the head and have the silk go from 12" at foot to 24" at the head. Seams will take at least an inch off and will give you just what you're looking for.

Instead of worrying about windproofness of a liner when used alone, skip doing that and just lay the 40f bag partly on top of you to adjust for comfort. That is one advantage of using a quilt in the first place.

Bob thanks for the silk source!

Aaron, thanks for the tips. I'm having trouble understanding your tapering idea. Are you imagining a liner-style that you slip into, or just as a sheet? I don't understand the shorter silk thing though. The three things I have to consider for design are 1) the ability to lay on it while being covered by it (laying on a foam mat is worse than nylon), 2) no contact with nylon, 3) doesn't fall off easy (so either a wide sheet, or less wide sheet with velcro, or liner-style)

John, I could, but in warm weather, I'm really bothered by nylon and even a 40f quilt is too much. Even in cold weather I'd prefer something else. In very warm weather, I like to have at least something covering me.

Another option for Silk, is Dharma Trading company. I usually find them cheaper (on average) than Thai silks, though it's been awhile since i've compared them. I've bought most of my silk via Dharma Trading company and it's pretty good quality, and good customer service.

If you're into silk p.j.'s and baselayers, they also have some of these for reasonable.

Just keep in mind, the lighter the silk, the less durable it will be. Silk is not particulary cheap material and so you may want to strike a balance between cost, durability, and lightness in a more long term sense.

Silk especially lightweight stuff, btw, i find rather hard to sew, but then again i'm more or less a newbie sewer.

Another tip for silk, if you want to prolong the life of it, don't sleep with it on bare skin too much (some kind of baselayer helps a lot). Body oils and body acids do eventually break it down and weaken it. Some folks have different body chemistry than others due to diet, stress, lifestyles (types and amounts of exercise), and/or genetics. Some folks like myself who are very calm/relaxed and centered most of the time, with a very alkaline forming diet (very high in non starchy veggies, some fruits, and not a lot of protein–mostly vegetarian), and more aerobic activity will tend to not affect silk so much. Folks with higher stress levels, high amounts of anaerobic activity with little aerobic exercise, and/or more typical SAD type diet, will produce and secrete higher amounts and degree of acidity and damage silk faster.