Tattoo Magic( Lords of Darkness, p. 189)
You can create tattoos that store spells.
You can create single-use magic tattoos.
You can create a tattoo of any spell of 3rd level or lower that you know and that targets a creature or creatures. Creating a tattoo takes 1 hour, and it must be inked onto a creature with a corporeal body. When you create a tattoo, you set the caster level. The caster level must be sufficient to cast the spell in question and no higher than your own level. The base price of a tattoo is its spell level x its caster level x 50 gp. To create a tattoo, you must spend 1/25 of this base price in XP and use up raw materials costing half this base price.
When you create a tattoo, you make any choices that you would normally make when casting the spell. The bearer of the tattoo is the only one who can activate it and is always the target of the spell. Activating a tattoo requires the creature to touch the tattoo with either hand (the hand does not need to be empty). Activating a tattoo is a standard action that does not draw an attack of opportunity.
Any tattoo that stores a spell with a costly material component or an XP cost also carries a commensurate cost. In addition to the costs derived from the base price, you must expend the material component or pay the XP when creating the tattoo.
Normally a magic tattoo uses a magic item space on the creature's body. Fore example, a creature with a tattoo on one of its hands could not gain the benefits from a magic glove on that hand. Likewise, a creature with a magic tattoo on its back does not receive the benefits of a magic cloak, cape, or mantle. In effect, the magic tattoo is always the first item "worn" on that part of the body, negating the effects of all other items. A tattoo can be created that does not use a magic item space, but the base price of such a tattoo is double the normal value.
A magic tattoo can be erased with an erase spell as if it were magic writing. Failing to erase the tattoo does not activate it.