Copper, when exposed to water and air, will slowly develop a verdigris patina on its surface, transforming its bright bronzy gleam into a tarnished teal skin. So why have the copper caps enclosing each bottle of Tito's Handmade Vodka resisted any sign of aging at all? Because they're made of plastic, of course. Like certain other controversial aspects of the vodka's packaging, its iconic copper detailing is more superficial than material.