Bronzewood (3.5e Equipiment)
From D&D Wiki
Bronzewood is a special type of wood that can replace steel in most items. It costs the same as mithral, but light armors can't be made with it (except chainshirts), neither can chains or spikechains. Any item that's normally made of metal is 10% lighter (i.e., a bronzewood longsword weighs 3.6# instead of 4#). Furthermore, the armor check penalty doesn't apply to hide checks in woodland areas.