Painting metal?

Kind of off topic I guess

But what color do you guys think is easier to paint? Flat black, or gloss? I like flat black, and it seems like it would be a little easier to paint consistent?

Im going to paint my bike frame black, I looked into PC, but for a 100 bucks, im a 4th of the way to a new frame.

I know Linc paints cars and stuff. So what do you recommend And what other little things should I buy? Different sand papers, clear coat, etc

Thanks!