You convert a non-masterwork item into its masterwork equivalent. A normal sword becomes a masterwork sword, a suit of leather armor becomes a masterwork suit of leather armor, a set of thieves’ tools becomes masterwork thieves’ tools, and so on. If the target object has no masterwork equivalent, the spell has no effect. You can affect 50 pieces of ammunition as if they were one weapon. You decide if the object’s appearance changes to reflect this improved quality.
The material component for the spell is magical reagents worth the cost difference between a normal item and the equivalent masterwork item (typically 300 gp for a weapon, 150 gp for armor, or 50 gp for a tool). If an object has multiple masterwork options (such as a double weapon, or a spiked shield that could be made masterwork as a weapon or armor), you choose one option of the object to affect (though you can cast the spell again to affect another option).
Section 15: Copyright Notice - Pathfinder Roleplaying Game Ultimate Magic
Pathfinder Roleplaying Game Ultimate Magic. © 2011, Paizo Publishing, LLC; Authors: Jason Bulmahn, Tim Hitchcock, Colin McComb, Rob McCreary, Jason Nelson, Stephen Radney-MacFarland, Sean K Reynolds, Owen K.C. Stephens, and Russ Taylor.