New discs, black on one side

[Targarama]

I know I need to clean off new brake discs before use with some white spirit or similar, but the inside side of the new front discs I've just received are coated in some kind of black paint. Should I give them a scrub with emery paper or similar, or just leave the pads to do it? Since the pads will be new too I'm think I should give this black paint a help to come off in the contact area.

Any input?

[GreenV8S]

Clean any wax/grease off the braking surface with brake cleaner. Any paint on the discs will get cleared off pretty sharply when you use the brakes.