The ceiling panels are prefinished furniture grade maple plywood. The cleat systems seem expensive, so typically we just fasten the panels with screws then finish with plugs or wood putty.

Thanks so much for your response, and especially for including your thoughts on cost and attachment options. Much appreciated!

Sara

You are most welcome - good luck with your project!

Do you have to attach the plywood to drywall?

There isn't a reason to include drywall under the plywood. Just fasten it to strapping on the roof framing.