people use spinnaker sail cloth for tarps.
i bought some kite cloth a while back. it feels like magazine paper, it was listed as .75 oz, but the coating is extreme, and it is much heavier than silnylon.
yes, i also would like to know if the hh is cut on the bias. can anyone tell? the older hh's that i've laid in didn't have anymore stretch than a reg. cut hammock. if they were cut on the bias, i would think there would be a very noticable amount of stretch. hennessy has alot of crazy stuff in his patents that he doesn't actually use in his commercial designs.
i would think a hammock that was cut on the bias would stretch way too much, causing sever shoulder squeeze. for instance, 1.1 stretches more than 1.9 and so it has more shoulder squeeze. a bias cut would stretch way more than even 1.1, i would think.