I test built the basic shape of the Triple Feather Plume to see if it would fit the Bicorne hat!
Now that I can be sure that it does (I had to make the right side of the plume a little bit differently to fit the curve of the papercraft bicorne!) I can start adding in the details (the "grooves")! ;o)
Like almost all LEGO parts, the plume can also be used on other parts, like the Archer's Hats of the Forestmen: