Painting Rims!?!?!

How do you people paint the rims, because i see people that paint the rims black in the middle and stay chrome on the outside? Do you put tape so the black paint doesnt touch the chrome or wut?

mask off the outer lip, and just take some light sand paper and ruff up the center spokes clean it and spray the spokes black, and remove the tape and then you have black spokes and a chrome lip.