You can make this in buttercream. Use a large rose/petal tip. Maybe a Wilton 123 that would allow the top edge to be away from the cake more. Or try a Wilton 124, 125, or 127 for a wider band. Depends how wide you want the bands to be.
i would practice on a dummy and see which you like best.
Hope that helps.
Teri, Ontario, Canada http://www.TeriLovesCake.ca
