cajones is boxes. I think the word you're looking for is cojones.
ooh- and hammock related... sounds like sewing netting is complicated, any pointers? Personally, I would hem the net, putting the edge in a strip of fabric (kind of like the grosgrain ribbon on a maccat tarp) and then fiddle with the zipper.
I'll let HE answer for sure, but I think he just used rolled hems for most of his bug bivy. As far as I understood, the only places he added grosgrain were some of the stress points around the zipper area.
"Physics is the only true science. All else is stamp collecting." - J. J. Thompson