It should be washed to allow it to regain its natural elasticity. If it still doesn't work, it is recommended to thread a thin strip of beef tendon through the middle of the fabric, or sew a little bit off both sides of the hat with a steal stitch. .

After washing the hat, tie it up with a rope. It can be divided into 3 to 4 sections according to the length of the hat. Rubber bands can also be used. Use the same method to dry clothes naturally, tie them up in sections, and wait until they are dry. Remove the rubber band or rope later. You can also use an iron to dry it.

Or the method is as follows:

Tighten the hat (according to the lines of the wool, there must be no wrinkles), flatten it and iron it directly. If it is not air-jet, you must first Wet the hat; there is another way, if there is no soldering iron available, you can also use an iron cylinder (stainless steel) or just use freshly boiled water (100 degrees!) to iron directly. Wet the hat with warm water first.