Measure your head
As you might have guessed, the first thing you’ll want to do is measure the head of the person who you are making your hat for. The circumference of the head is the most important measurement and needs to be taken from the middle of the forehead, just above your ears and then midway at the back of the head. Make sure the tape is level around the head and measure three times to get an accurate measurement.
A hat’s crown is the bit that sits on top of your head and this needs to be wide enough for your head. When blocking or making your crown you should add half an inch to the head measurement to make sure that there is enough room for the inner headband to cover the seams of the brim.
Depending on the type and style of hat you are making you may want to add a sideband which will control where your hat will sit on the head. The height of the sideband will affect where the hat sits on your head with slimmer bands sitting lower on the head then deeper bands. Remember to test with different width sidebands to see which produces the desired effect.
For most types of hats the brim will be attached to the bottom of the crown and a top stitch should be used to join the brim and the bottom of the sideband together, ensuring a perfect fit. Once the brim has been attached you can move to the finishing touches of the hat.
As well as adding extra strength, warmth and comfort, lining a hat help to hide all the unsightly joins between the brim and the crown. The easiest way to line a hat is to use a rectangular piece of lining fabric and line the inside of the crown leaving the top unlined. This has the added benefit of letting the hat breathe.
The final stage to complete your hat is to fit a sweatband on the inside, this will help to prolong the life and make the hat comfortable to wear. If at this point the hat is slightly too large for the wearer; then you can use hat sizing tape to help adjust the size and improve the fit.