1. Chrome Finish
Chrome finish provides an extremely polished, reflective effect similar to a mirror. With extremely high shine and reflective, this finish is popular among enthusiasts and it has the ability to completely change the look of a vehicle. The downside of this type of finish is that it can require a fair amount of maintenance to keep the wheels clear of chemicals, brake dust, and other contaminants that can quickly compromise its shine. The mirror finish is effectively achieved by chrome plating the wheel with a combination of nickel and copper. Chroming was initially designed to protect against rust, but the automotive scene has seen it develop into a fashionable trend.
2. Milled Finish
Raw machined aluminum that has been cut with a milling cutter, not clear coated unless indicated.
3. Machined Finish
A machined finish is applied by spinning the wheel on a Computer Numeric Control (CNC) lathe. The lathe bit cuts a small amount of metal off the face of the wheel, flattening and polishing the surface to a high metallic shine. This process leaves tiny concentric lines in the finish, giving it an effect somewhat like the surface of CD.
4. Painted
Consists first of a primer sprayed onto prepared bare metal, followed by an automotive style paint and a protective clear-coat that seals the wheel and finish against water and air that can cause corrosion. Wheels are painted with an HVLP (High-Velocity Low Pressure) spray gun, in much the same process by which auto paints are applied. Most original equipment wheels are sprayed with a liquid clear-coat.