i got a leather with studs and everything but i dont know what kind of paint to use, i used modeling paint but after about 2 weeks its started cracking
Being arrogant isn't very advanced or mature - and it's always good to see if there are other options around by asking. You never know when someone else might prove you wrong.
Well, a little googling and I found this paint which claims to not crack even on leather sneakers where it creases. They show some examples of it on after 6 months wear.
Just saw this on the angry young and poor website in the description of a leather jacket:
"if you want to paint it, the best thing to use is Testors Paint Markers. You may have to re-apply after a while if it starts to crack, but it stays on and it comes out bright"