Bond

Touch a simple weapon or armour of medium or lighter weight, for 1 hour after casting the chosen material and item are melded together.

Wood gives a +1 to ac and attack rolls Stone gives a +2 to ac and attack rolls Metal gives a +3 to ac and attack rolls and a +2 to damage (this depends on the metal Mithril > iron and the DM's discretion)

Higher spells slots allow stronger materials (stone at 3rd and metal at 4th) to bond to Weightier armour and martial weapons (3rd level or higher)