To create
magic armor, a character needs a heat source and some iron, wood, or leatherworking tools. He also needs a supply of materials, the most obvious being the armor or the pieces of the armor to be assembled. Armor to be made into
magic armor must be
masterwork armor, and the masterwork cost is added to the base price to determine final market value. Additional magic supplies costs for the materials are subsumed in the cost for creating the
magic armor-half the base price of the item.
If spells are involved in the
prerequisites for making the armor, the creator must have prepared the spells to be cast (or must know the spells, in the case of a
sorcerer or
bard), must provide any material components or focuses the spells require, and must pay any XP costs required for the spells. The act of working on the armor triggers the prepared spells, making them unavailable for casting during each day of the armor's creation. (That is, those spell slots are expended from his currently prepared spells, just as if they had been cast.)