Fill the iron with water and set the heat to high.
Hold the feather on the ironing board so that the middle curves up towards you.
Hold the iron slightly over the feather but do not touch the feather with the iron.
Press the steam button as you move the iron over the length of the feather.
Set the iron aside. Press the feather against the ironing board to straighten the quill. Gently push the quill of the feather against the curve to encourage straightening. If it is not pliable enough, add a little more steam.
Take the feather off of the ironing board once you have straightened it out. Place the feather in the middle of a heavy book. Shut the book and place one or more other heavy books on top of it. This will ensure that the feather stays straight.