For what its worth, that is pretty thin fabric.
maybe a slightly heavier ripstop nylon would be more durable?
The seattlefabrics.com web site has good info about fabrics and applications.
they list heavier ripstop coated nylon for tent fly use, I think Super-K or something like that, check it under their nylon fabrics products page. It doesn't look much more expensive than the taffeta which isn't ripstop.
I am learning as I go here and relying on the expertise of my sailmaker friends. But I do know that the "thin-ness" is influenced as much by the coating as it is by the fabric. I would prefer a lighter fabric with a heavier coating for pack-ability and water resistance. We are still looking at fabric choices but trying to split the difference between weight and compactness.
Also, the fabric you are mentioning is very expensive. There are other, more affordable fabric options that do the job as well or better. If somebody wants one made of Super K, I bet Karl would make one. But be prepared to pay. Also, I have worked extensively with rip-stop nylon having cut, stuck, and stitched countless spinnakers together. I find it very difficult to work with. Karl is good at it, but my experience is that it is harder to cut and sew than other fabrics...meaning, the price may go up.
One clear theme in the first several posts is cost. We want to keep the price down, deliver a better fly, and get them into the hands of FP owners quickly (something that FRP cannot seem to do).
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