The copper layer is the first decorative deposit applied to the wheel. Copper being a relatively soft metal will actually fill in many imperfections in the casting. This prepares the wheel for the remaining plating baths.

Once the copper is fully deposited onto the wheel, it is again washed and polished by hand. This further smoothes out the surface and begins to generate the final deep lustre CalChrome's wheels are known for.

This is where many chrome platers will cut corners with the bare minimum deposit, or worse yet leaving out the copper layer entirely. Often times, when a copper layer is added, it is not a heavy enough deposit or it is not polished.