How do I paint shiny brass light fixture with black chalk paint?

You do not need chalk paint to paint your light fixture. You can just spray it with spray paint.

Any black paint will work - I've done it lots of times with any old spray paint! Just take off anything you don't want black - and tape off the parts that can't be removed. Such a quick project! :)

Super easy to do with spray paint. If your heart is set on a specific chalk paint you could spray on a single layer of matte spray paint, allow it to dry completely, and now your chalk paint will have something to adhere to. Have fun :)

Thanks for the answers. I was thinking I'd have to sand it, glad tohear I can just use spray paint.