The thick, sturdy plates of an umber hulk's hide can be used to craft sturdy, powerful armor and shields that offer their wearer protection against psychic attack.
Any half plate or shield created with umber hulk hide adds +2 to armor modifier and has immunity: mind affecting spells. Note these are separate item properties. The +2 AC bonus does not stack with further enchantment bonuses crafted to the shield or armor; the bonuses overlap. For example, an umber hulk heavy shield subsequently enhanced with a +3 enhancement bonus gives a total of +5 shield bonus to the user's AC (the shield's base +2, plus the +3 enhancement). Note however, that the immunity to mind-affecting spells remains, making umber hulk still quite valuable (especially for a fighter-type with low will saves).
Notes[]
Crafting armor out of the hide of an umber hulk requires considerable skill, as it adds 17 to its difficulty class.
Umber hulk hide may be used to craft any shield (including tower shields) but only Half-plate and Breastplate armor; this is despite the misleading descriptors calling for "metal ingots".