Hats, while lending protection to the head and face from the sun and wind, are relatively fragile accessories. Most people have had the unfortunate experience of someone sitting or stepping on their prized hat, or a favorite hat getting squashed in a suitcase during travel. Even if your hat has completely lost its shape or has a large dent, there are measures you can take to restore it to its former glory in just a few days.
Press your hand against the inside of the hat, pushing the dents out of the hat as best as you can.
Fill a kettle with water and place it on the stove over high heat. Allow the water to come to a boil, producing a great deal of steam. Lower the burner to low or medium heat so the kettle produces a continuous amount of steam without using all the water right away.
Hold the inner portion of the hat over the flow of steam, directing the steam to the dented or more flattened parts. Slowly rotate the hat to distribute the steam all around the inner portion of the hat. Continue to do this until the hat resumes its normal shape. The steam helps loosen the fabric stiffener of the hat.
Stuff the inner portion of the hat with tissue paper. It's important to stuff the hat tightly so the tissue paper reinforces the work of the steam and supports the proper shape of the hat. Place the hat on a flat surface for several days, letting the fabric stiffener re-bond in the hat's proper shape.