Had my door handle and painted mirrors done with enamel by a pro down in Mazatlan 3 years ago and they are still looking really fine. But, I also got out of the habit of placing my thumb on the outside of the door latch handle, instead using the inside area to pull it open. So no early wear from my thumb. The mirrors and that handle look brand new. My basement handles were painted at the same time and they are all fine still too.
Pretty sure he used epoxy based paint. He was able to match the paint really well for the basement compartments.
Here's my ad free article about it:
Painting...