Coil coating is the continuous and highly automated industrial process for efficiently coating metal coils. Because the metal is treated before it is cut and formed, the entire surface is cleaned and treated, providing tightly-bonded finishes. (Formed parts can have many holes, recessed areas, valleys, and hidden areas that make it difficult to clean and uniformly paint.) Coil-coated metal (often called prepainted metal) is often considered more durable and more corrosion-resistant than most post painted metal.
Annually, 4.5 million tons of coil-coated steel and aluminum are produced and shipped in North America, and 5 million tons in Europe.  In almost every five-year period since the early 1980s, the growth rate of coil-coated metal has exceeded the growth rates of either steel and/or aluminum production.