I purchased 500D coudura at special price of $ 6.25 yard from rocky woods fabrics. I really like working with 500D cordura it only weighs 6.5 ounces a square yard and is more durable than the lighter weight fabrics. I was able to make each pack for under $15.00 including everything and the packs both weigh under 30 ounces.
I made a 28 liter clamshell and a 40 liter large mouth pack. I have been wanting to design a clamshell pack for awhile. The pack has two deep water bottle pockets and shov-it front panel used in compression and to stuff a jacket in and a expandable front zippered pocket.
The large mouth pack is a top loader you can dump everything in and use a short ridgerest pad as virtual frame it also use a z rest pad sewn in to the back panel for breathability and to use as foot pad when sleeping.
The pack has top compression system on the sides of each zipper and a short shock cord on top to put a wet jacket under. The pack has a large shov-it front panel that holds my OR aurora bivy and ground cloth,large deep water bottle pocket that carry bottles and deep enough for my sea to summit umbrella also,expandable front zippered pocket.
Large mouth pack photos:
Clam shell pack photos: