The ceiling tiles came from a building they demolished in downtown Albuquerque about thirty years ago. They were in a panel of 8 squares. We cut them into individual squares. I then use a steel brush to get all the loose paint and rust. They are then sealed with a clear coat twice both sides. I use oil paint to decorate the center, and clear coat it two more times. The tin is mounted on Masonite with a hanger cut in.
More info: metal-unicorn.com