Light BPack Fabric

Extremtextil has some 160D cordura.
http://www.extremtextil.de/catalog/Cordura-160den-uncoated::724.html?XTCsid=ea465f23067c2cb4aba2b394eb0c68a8
I haven't checked, but they may have other fabrics that meet your requirements as well.

They also have a 210d with PU coat and a X-Pac VX07 at 3.8oz/sqyd and 4.9oz/sqyd respectively.

http://www.extremtextil.de/catalog/Nylon-210den-PU-coated-130g-qm::184.html?XTCsid=ea465f23067c2cb4aba2b394eb0c68a8

http://www.extremtextil.de/catalog/X-Pac-VX07-Laminate-165g-sqm::851.html?XTCsid=ea465f23067c2cb4aba2b394eb0c68a8

Sorry, got your weight range confused (I thought Gridstop was heavier, not 4oz/sqyd). Since you're looking at between 2 and 4 ounces (70D silnylon is ~1.9oz/sqyd) I found a few others.

They have a 110D silnylon at 2.75oz, an PU coated nylon at similar weight but unspecified denier, and a 75D ripstop sil-poly.

ZPacks also has a 2.92oz/sqyd cuben-nylon hybrid that seems well liked (PRICEY though).
http://zpacks.com/materials.shtml

Ahh, I totally forgot to mention that I'm avoiding cuben just for cost considerations.

Yeah weight range sweet spot would between 2-3.5oz.

Some of the Extremtextil stuff looks like it would probably work but I'm US based. Guess I don't have much info in my profile. Good ideas all.

Dustin,

Do I remember correctly that you wanted to do a MYOG MH Thruway at some point. What fabrics are you thinking of using?

Yes, I am looking to make a thruway clone (I still haven't seen one in person though and still pretty content with my Talon 44). Fabric wise I haven't decided yet. I like the thruway for it's design elements more than fabric, although there's nothing wrong with what they use. Depending on how many yards my pattern will need, I may just go with some cuben/nylon hybrid from zpacks for the pack and maybe a lightweight cordura for the bottom.

I tend to be way too methodical and slow on the design process since I hate wasting money and generally don't have much spare time. So it'll probably be end of summer (I have a tarp or two and bivies in queue before I tackle a pack).

R,
I've looked at the cuben/nylon laminate, just under 3 oz, and one of the very light Xpacs around 3 oz, and did not like the stiff, crinkly quality of the fabric. Was also concerned with how durable the Xpac would be, with the very thin fabric portion of the laminate, and how well stitch lines on the cuben would hold.

Also looked at 1.9 oz silnylon, available from Seattle Fabrics, weighing around 2.5 oz. with coating. Unlike the stuff Warmlite uses for stuffbags, it has a double coating, and is therefore a little more waterproof, but not so much as Xpac.

In the end, decided on the 4.9 oz Xpac purchased form Rockywoods (VX07, I think). It is much more waterproof than a couple of dyneema/spectra gridstops I looked at, and i think it will be just as durable. The weight penalty for a 4.9 oz over a 2.5-3 oz material will be 2-2.5 oz for a pack using around one square yard or less of material for the outer fabric.

For me, 2-2.5 oz. is a cheap price to pay for a pack that will remain waterproof, hold up to abrasion and wear and tear, and last for many seasons. I made a pack of 1.9 oz ripstop nylon with a stormproof coating that brought it up to close to 4 oz., and while totally waterproof, it started to show serious abrasion after only one 20 day trek – in high country, not bushwacking. Not going there again.

Thanks for your thoughts. Lots of good discussion on pack fabrics recently with Lawson's thread.

Samuel,

My thoughs mirror yours regarding the VX07, good stuff. Thanks for pointing out the fact that total fabric weight is really a small component of overall weight and varies little even when sacrificing other important qualities like waterproofness.

I'm likely to stick a mix of Xpac VX21, VX07, 1.9Sil and Dyneema X since that is what I have and I'm fairly happy with their attributes. Always interesting to discuss what else is out there!