It was based upon what material to compare the density of life fibers too. If it was deemed to have the same density as like steel, she'd be 5-C. It was denied since durability =/= density, and there are fibers with comparble durability as steel which are much less dense.
I've tried everything I could man. But it doesn't look like we're really getting anywhere in that thread. If my buddy yields anything meaningfull from that size calc I sent to him, I'll post it there as a last resort. But from this point on, I can't really argue that thread anymore, and am unfollowing it.