I have purchased some fur felt hat bodies (beaver/ rabbit) on discount to make fedoras with 3.25-4'brims/ 3.5-5" crowns. I am having a heck of a time getting the brims to flatten. They seem to lay flat but when they are worn they curve in the front and flip on the sides. I don't hate the way they look with the curved brim, but I would like to be able to create some with totally flat brims. I have purchased spray shellac and Biehl hat stiffener, and the fabric is stiff, but not razor flat like I want it. Not sure if the felts aren't treated with enough stiffener or maybe they are too tight when worn and flip down. Or is it operator error? Any tips would be appreciated.