I'm going to make a light down quilt adjunct for my 15F bag. I would like to use the most breathable fabric I can get. This quilt will only be used as add-on to the sleeping bag. (I first made such an overbag 40 years ago, but for various reasons, that one is no longer suitable.)

I notice that most of the fabric sold by places like thru-hiker.com has a DWR coating and is described as having low-to-moderate breathability.

Where can one get 1.1 oz/yd^2 (or lighter) nylon/synthetic, woven or microfiber, down-proof cloth that does NOT have DWR?

MoapaPk wrote:I'm going to make a light down quilt adjunct for my 15F bag. I would like to use the most breathable fabric I can get. This quilt will only be used as add-on to the sleeping bag. (I first made such an overbag 40 years ago, but for various reasons, that one is no longer suitable.)

I notice that most of the fabric sold by places like thru-hiker.com has a DWR coating and is described as having low-to-moderate breathability.

Where can one get 1.1 oz/yd^2 (or lighter) nylon/synthetic, woven or microfiber, down-proof cloth that does NOT have DWR?

From a sailmaker. It's called spinnaker cloth (0.75 oz/yd^2). Of course, that might be a bit stiffer than you are looking for.

Try asking your question on the MYOG forum on Backpacking Light.

Also check out the offerings of Rockywoods and Seattle Fabrics.

Isn't spinnaker cloth waterproof? I checked Backpacking Light -- they wanted me to subscribe. Rockywoods doesn't seem to have light down-proof materials; Seattle Fabrics gets down to 1.1 oz ripstop: http://www.seattlefabrics.com/nylons.html#1.1 oz RS0

MoapaPk wrote:Isn't spinnaker cloth waterproof? I checked Backpacking Light -- they wanted me to subscribe. Rockywoods doesn't seem to have light down-proof materials; Seattle Fabrics gets down to 1.1 oz ripstop: http://www.seattlefabrics.com/nylons.html#1.1 oz RS0

Mt wife and I have been using down jackets, down bags, and down comforters from Western Mountaineering for many years. They use the best, as far as I know, micro fiber, down-proof, breathable material there is. I don't know if they sell fabric to the public or not, but it's worth a shot.

http://www.phdesigns.co.uk/techfab.php

I have a Minim in MX, it's very light, downproof and not water-resistant. I'm not sure what MX is generically, but it's like a very light original Pertex. Maybe ask Peter: http://www.phdesigns.co.uk/contact_us.php

Thanks all. I ended up buying non-dwr 1.1 oz/yd^2 ripstop "seconds," where the cloth is marked irregular only because it has markings (meant for laser-cutting, military apps) on parts. Not the lightest, but inexpensive. I figure I'll use <4 yards*2, so I won't give up more than an ounce.