Grips help Please

Hello everyone,

Guys I need some help. I bought some Battistini Round Hole Grips by Arlen Ness on the throttle side was change to the one u are seeing and I had to paint the handle bar ends. But now when I work the throttle the paint scratches off little by little. What paint can I use for the handle ends to hold up to the working of the throttle grip through time...