The Stetson hat, recognized as the American cowboy hat, is a high crown, wide brimmed, fur felt hat. Some consider the design to be a modified sombrero. Today a Stetson type of hat can be made out of straw, leather or felt. But the original Stetson hat was, and still is, made from a highly complex felting process using the fur of domestic rabbits, mink, chinchilla, wild hare and beaver. Block a Stetson hat to renew its original shape or to change the hat size.

Remove everything from the inside of the hat. This includes the sweat band and the lining if there is one, as well as any tags. Remove the hat band on the outside of the hat.

Find a wood hat form that's the size the hat is to be re-blocked to. Wood forms are a specialty item, so in lieu of a wood hat form try using a Styrofoam wig form for smaller hats or make a hat form out of a block of Styrofoam for larger hat sizes. Shape the Styrofoam for the hat form like the inside of a mixing bowl. First cut the Styrofoam into a block and then use wood rasps to file it into the correct shape and circumference.

Set the Stetson hat over a corresponding hat form size if re-blocking to renew its shape. If the size is going to be increased, set the hat on top of a larger sized wood form. Use T-pins to pin it to a styrofoam form. To decrease the hat's size, use the correct size hat form. Expect to increase or decrease a Stetson hat size by one size.

Steam the felt hat with a clothes steamer. The combination of heat and moisture makes the felt more pliable. Shape the hat if re-blocking to renew its original shape. To increase the size, carefully stretch the hat further down over the wood form being careful not to tear the felt during stretching. For Styrofoam hat forms take the T-pins out and carefully work the hat further down over the Styrofoam hat form. Re-pin the hat to the form to hold it in place. To decrease the size, steam the felt, let it dry and repeat until the felt hat shrinks to the new size.

Steam the hat again once it's reshaped or stretched to the new size to set the felt. Leave the hat on the form until it's completely dry.

Put back the lining and the sweat band after re-blocking is complete. Reattach the headband to the outside. If the size of the hat has been increased, splice in a section to the original sweatband or purchase a new stock sweat band. If the head band is adjustable, adjust the size after blocking to re-size the Stetson. If it's not adjustable, purchase a new stock head band. If the hat size has been decreased, cut out a section of sweat band before reattaching and tighten the existing head band.

Using a soft brush, start at the left side of the hat and brush the surface in a counter clockwise direction all the way around the hat to refresh the surface fibers of the fur felt.