Shell Armor Mod 1.7.2
This armor provides no traditional percentage reduction, going for clean damage breaks instead.
A plate made out of 16 clay layers, strapped to the chest.
The first material used was clay, due to it being easy to mold, but experimentation has shown that both iron and obsidian work quite well.
Plus, they can be layered deeper, too, since I can craft them thinner.
32 layers or iron, like a good blade. Except heavier.
64 layers of waver-thin obsidian.
As a bonus, the special properties of obsidian also seem to protect against magical damage.