Creature and planeswalker spells you cast have affinity for artifacts. (They cost less to cast for each artifact you control.)
[+2]: Tezzeret, Master of the Bridge deals X damage to each opponent, where X is the number of artifacts you control. You gain X life.
[−3]: Return target artifact card from your graveyard to your hand.
[−8]: Exile the top ten cards of your library. Put all artifact cards from among them onto the battlefield.