MAKE YOUR OWN FELT HAT STIFFENER: Pour 1/4 cup cornstarch into a medium-sized cooking pot. Add 1 cup water to the pot. Bring the pot to a hard boil on high heat. Stir periodically. Reduce the heat to medium and allow the mixture to simmer until the cornstarch is completely dissolved and the mixture has thickened and is clear. Remove the mixture from the heat and allow it to cool completely before applying it to the felt hat with a small paintbrush.