A interesting idea which really does not come off. Descriptions which do not really say enough No costs or why they are different than any other armour other than by discription. IE

We have a real gem here. Every shield is tested by being dropped in a swamp, left outside in the rain and dribbled on by a giant toad, and not one of these shields leaves our warehouse with the slightest damage. We cannot promise it will be unmarked by sword blows, but mere damp and dribble will have no chance.

But what does it do? What is different about it? Not there best work