Enter silkworms. They produce fragile silk, but they have heaps of natural potential as high volume producers capable of spinning approximately a kilometer of silk thread in a few days, with a long history of successful human cultivation.
In Thailand in 1999, the Rajamangala Institute of Technology reported that it had developed body armor using only standard, low-cost silkworm silk. Tests indicated that 16 silk layers could stop a 9mm bullet, and that the vests could provide protection against high-velocity rifle shots as well as .22 caliber handguns.
More recently, silk has even been successfully exploited for "blast boxers."
The latest breakthrough was achieved by the University of Wyoming and published in Proceedings of the National Academy of Sciences this month.
According to their publication, they have succeeded in genetically modifying silkworms to produce a combination of worm and spider silk that is as strong as spider silk.
Arguably, the Holy Grail for Spidey body armor would be cracking the bark spider, reputedly 10 times stronger than Kevlar, and then applying these new silkworm factories.