Powder coating is one of the most durable exterior finishes available today. It is used on many metal items that are exposed to the weather because, as a finish, it is the best way to ensure durability, weather resistance, and color retention. A powder-coated finish is part paint and part polyester sealer/resin. The finish is applied as a powder, electrostatically, and while held to the metal this way, is baked in an oven. It is baked at a hot enough temperature so, in effect, the outside layer of the metal fuses with the melted powder forming a hard, weather-resistant finish.