Many hats come in one size only. For people with smaller heads, this means that many hats are too large and will not sit snugly on their heads. Luckily, making a hat smaller is much less difficult than making a hat larger. You can make a hat smaller using several commercial or homemade products designed to thicken the width of the hat so that it better fits your head. Use the commercial bands if you can find them, or make your own at home.
Purchase a cap liner to wear under your hat. The hat liner fits snugly over the head and adds about half an inch of width to the head. This kind of liner requires no special installation and is removable. The problem is that it may make your head hot.
Try using a hat sizer band if the cap liner does not appeal to you. Peel back the adhesive strip and press the band into the inside of the hat, behind the sweat band. Trim off any unnecessary band with scissors.
Add a second layer of banding if the hat is still too large.
Cut 2-inch long strips of weather stripping with scissors.
Peel back the sweat band of the hat. Peel back the paper covering the back of the weather stripping, exposing the adhesive strip. Place one strip behind the band and press in place. Press the adhesive side of the strip against the hat, not the sweat band.
Try on the hat for fit. Add additional strips of weather stripping around the hat behind the sweat band until the hat fits.
Add a second or third layer of stripping, if necessary, to keep your hat on snugly.