Then the ideal armor must be sea snail teeth woven together with spider silk. This advancement could save millions in mythril and adamantine.
So many questions and quests.
For example the spores in the Emerald Sea, where the hero is from, instantly grow into massive vines that destroy everything in their path. That makes sailing rather dangerous.
The story is whimsical, perhaps an adult fairy tale (or just a fairy tale?), so I don't know if it fits your taste.
And I think there is one more similar spider civilization book that's also popular – A Deepness in the Sky by Vernor Vinge.