I tried a search, but I didn't find exactly what I was looking for, so...
I have a black nutria felt homburg that used to have a nice dip in the front brim. It has let go as the hat broke in, and I was hoping to get it back with some spray hat stiffener. I have never used any stiffeners before. Could I get some recommendations for sprays that would be safe for black nutria? I don't want helmet hard, just enough to give it some hold.
Don't do it! If you do use stiffener, use it sparingly, from the inside, and in multiple applications to ensure you haven't overdone it. Better yet, PM me & sell it ;-)
"Faint hat never won fair lady."