The basic method: crown first, then attach the brim
A brimmed hat is sewn in two main pieces: the crown (the part that covers your head) and the brim (the flat or curved part that extends outward). You sew the crown together first, then attach the brim to the bottom edge. The brim itself is usually two layers of fabric sewn together, then stitched to the crown with the raw edges hidden inside.
The order matters because the crown needs to be a complete circle before the brim can attach evenly. If you try to add the brim before closing the crown, you will have a gap where the back seam should be, and the brim will sit crooked.
Most brimmed hats use one of two construction methods: a flat brim (like a baseball cap) or a structured brim (like a sun hat or bucket hat). The steps are similar, but a structured brim usually includes interfacing or buckram to hold its shape.
Key Takeaways
- Sew the crown pieces together first, leaving the bottom edge open, then close the back seam after you have attached the brim.
- Cut two identical brim pieces and sew them right sides together around the outer edge, leaving the inner edge open, then turn it right side out and press.
- Pin the brim to the crown with right sides together, matching the center front and back, then sew around the entire circle with a 1/2-inch seam allowance.
- Fold the brim seam allowance up into the crown and hand-stitch or machine-stitch it down to hide the raw edges.
- Interfacing or buckram in the brim keeps it from drooping and is especially important for larger brims or hats worn in humid weather.
Cutting and preparing the crown pieces
Most crown patterns include two to six pieces that radiate from the top center, like orange segments. Lay out your pattern pieces on the fabric grain line (usually the lengthwise direction) and cut them out, adding 1/2 inch beyond the pattern edge for seam allowance on all sides except the bottom.
If your pattern includes a lining, cut lining pieces the same way in a lighter fabric. Lining is optional but makes the inside of the hat look finished and protects the seams from rubbing your head. If you are using interfacing in the crown (common for structured hats), fuse it to the wrong side of the outer fabric pieces before sewing.
Stack your crown pieces in order and mark the top center point with a small notch or pin. This helps you keep the pieces aligned as you sew, especially if the crown has many pieces.
Sewing the crown together
Sew the crown pieces together by joining them two at a time, right sides facing. Start at the top point and sew down to the bottom edge, using a 1/2-inch seam allowance. Press each seam open as you go. Continue adding pieces until all pieces are joined in a circle.
Do not close the back seam yet. Leave a 2-inch gap in the back seam so you can insert the brim and attach it before finishing the crown. This gap will be closed after the brim is sewn on.
If you are using a lining, sew the lining pieces together the same way, but leave a 4-inch gap in the back seam (you will use this opening to turn the hat right side out later). Do not attach the lining to the crown yet.
Cutting and assembling the brim
Cut two identical brim pieces from your fabric, adding 1/2 inch seam allowance around all edges. If you are making a structured brim, cut a piece of interfacing or buckram the same size as the brim (without seam allowance) and fuse or glue it to the wrong side of one brim piece.
Place the two brim pieces right sides together and sew around the outer curved edge, using a 1/2-inch seam allowance. Leave the inner edge (the edge that attaches to the crown) completely open. Trim the seam allowance on the outer edge to 1/4 inch and clip the curves every 1/2 inch so the brim will lie flat when you turn it right side out.
Turn the brim right side out through the open inner edge and press it flat. The interfacing or buckram should now be sandwiched between the two fabric layers. Baste the inner edges together with a 1/4-inch seam allowance to keep them aligned while you attach the brim to the crown.
Attaching the brim to the crown
Pin the brim to the bottom edge of the crown, right sides together. Match the center front of the brim to the center front of the crown (usually marked on the pattern), and match the center back of the brim to the center back of the crown. Pin every 2 inches around the circle, easing the crown edge to fit the brim if needed.
Sew the brim to the crown using a 1/2-inch seam allowance, sewing all the way around. Remove the pins as you go. If your machine has a walking foot, use it to prevent the layers from shifting.
Now close the back seam of the crown by sewing the 2-inch gap you left open. Sew from the brim edge up to where the previous seam ended, using a 1/2-inch seam allowance. Press this seam open.
Finishing the seam allowance and lining
Fold the seam allowance of the brim up into the inside of the crown and press it flat. This hides the raw edges where the brim attaches to the crown. Pin it in place and hand-stitch it down using a ladder stitch (also called an invisible stitch), or machine-stitch it 1/8 inch from the fold using a straight stitch or topstitch.
If you are using a lining, place it inside the crown with wrong sides together and pin it around the top edge. Hand-stitch the lining to the crown seam using a ladder stitch, working from the inside. Fold the raw edges of the lining under as you go. Stitch the lining to the brim seam allowance as well, so the lining is anchored and will not shift when you wear the hat.
Close the 4-inch opening in the lining seam by hand-stitching it shut with a ladder stitch. Press the entire hat and try it on to check the fit.
Choosing interfacing and buckram for different hat styles
A lightweight interfacing (like fusible woven or knit interfacing) works for small brims or hats worn indoors. It adds structure without making the brim stiff or heavy. A medium-weight interfacing is better for medium brims or hats that will be worn outdoors. A buckram (a stiff, woven fabric) is the best choice for large brims, sun hats, or hats that need to hold their shape in humid weather.
If you are unsure which weight to use, start with medium-weight interfacing. You can always add a second layer if the brim droops after you wear the hat a few times. Buckram is harder to add later, so test the hat first before committing to it.
Some hatmakers use a combination: interfacing in the crown for structure and buckram in the brim for shape. This gives you a hat that is comfortable to wear but holds its form.
Frequently Asked Questions
What is the difference between a flat brim and a structured brim?
A flat brim has no interfacing and lies close to the head, like a baseball cap. A structured brim has interfacing or buckram and holds its shape away from the head, like a sun hat. The sewing steps are the same; the only difference is whether you add interfacing to the brim pieces before sewing them together.
Can I make a brimmed hat without a lining?
Yes. The lining is optional and mainly makes the inside look finished and protects the seams. Without a lining, the hat is lighter and faster to make, but the seams and raw edges will be visible inside. You can finish the raw edges with pinking shears or a zigzag stitch to prevent fraying.
How do I know what size brim to cut?
Use a pattern that matches your head size. If you are drafting your own pattern, measure around your head and divide by 3.14 to find the radius of the crown. The brim radius is the crown radius plus the width you want the brim to extend (usually 2 to 4 inches for a sun hat, 1 to 2 inches for a baseball cap).
What happens if the brim does not lie flat after I attach it?
The crown edge and brim inner edge may not match in length. Ease the longer edge by pinning and sewing slowly, letting the fabric gather slightly. If the brim is much larger than the crown, you may have cut the crown pieces too small or the brim too large. Check your pattern measurements and adjust before cutting new pieces.
Can I add a sweatband or elastic to the inside?
Yes. After you have finished the lining, sew a strip of sweatband fabric or elastic around the inside edge where the crown meets the brim. This keeps sweat away from the fabric and makes the hat more comfortable. Sew it by hand using a ladder stitch, or machine-stitch it with a zigzag stitch to allow for stretch.