SRD:Dragonhide

Dragonhide
Armorsmiths can work with the hides of dragons to produce armor or shields of masterwork quality. One dragon produces enough hide for a single suit of masterwork hide armor for a creature one size category smaller than the dragon. By selecting only choice scales and bits of hide, an armorsmith can produce one suit of masterwork banded mail for a creature two sizes smaller, one suit of masterwork half-plate for a creature three sizes smaller, or one masterwork breastplate or suit of full plate for a creature four sizes smaller. In each case, enough hide is available to produce a small or large masterwork shield in addition to the armor, provided that the dragon is Large or larger.

Because dragonhide armor isn’t made of metal, druids can wear it without penalty.

Dragonhide armor costs double what masterwork armor of that type ordinarily costs, but it takes no longer to make than ordinary armor of that type.

Dragonhide has 10 hit points per inch of thickness and hardness 10.