Silnylon, MYOG?

For silnylon try thru-hiker.com, owfinc.com, and i think seattlefabrics.com, but you'll probably be best with the first two. They should also have a wide array of zippers. How small are you thinking, there is defiantly a point where small zippers, even with pulls, will be a nuisance on VB gear, twisting and turning, and hard to hold with gloves.

Thanks for the information!

I was thinking zippers about 1/8" wide or so. Nothing terribly small, but not so big it's heavy and uncomfortable.

Hmm, I wonder how many yards I would need to make an XXL jacket?

I have found that some of the silnylons I have purchased from the above listed places leak. Try to test them by hanging water in them. Some hold water some don't.

speerhammocks.com also sells sil – the best ive used. He claims its first quality, and for under $9 a yard. some people will say noah lamport, but they have on 2 occasions given me the worst sil ive ever seen. ive used about 100 yards of it from different suppliers. also, speer sometimes has a very nice olive/brown for stealth. if not, questoutfitters.com

Do you test yours before sewing?

I suppose there's a reason that "seconds" aren't "firsts".

I was planning to stop by Noah Lamport to check out their products. If they're willing to provide swatches would it be possible to test a small piece for waterproofness, and would the test be representative of the whole roll?

Since I've never sewn with silnylon I want to try a project or two from cheap stuff. Also with my planned family tent requiring at least a dozen yards I was hoping to save money there as well.

what i was trying to say is that noah lamport sells "thirds"
if you think $3 a yard is too good to be true, it probably is
its not a risk I would take again… also, there are a bunch of hidden fees, cutting fee, high shipping, etc.
noah lamport (roger) cares nothing for the myog outdoorsman, go with one of US like Ed Speer or Paul Nanian.
just words of advice, but you can do whatever you want.