You touch a willing creature who isn't wearing armor, and a protective magical force surrounds it until the spell ends. The target's base AC becomes 13 + its Dexterity modifier. The spell ends if the target dons armor or if you dismiss the spell as an action.
a piece of cured leather
Expecto Medeis Armatus
Verbal Component (Alternative):
I summon magic to aid and protect, armor of steel to help deflect.