Draw a wedge shape onto a heavy piece of cardboard. The wedge should be about 6 1/2 inches long and 6 inches wide at the base. The sides of the wedge should arc as they taper down to the base. Use scissors to cut out the shape from the cardboard.
Step2
Lay your polar fleece fabric onto a flat work surface, wrong side up. Place your cardboard template onto the fabric and trace around it with a fabric-marking pen. Make a total of four tracings.
Step3
Use a yardstick or ruler and a fabric-marking pen to trace a long rectangle onto the wrong side of the fabric. The rectangle should be about 20 inches long. Decide how wide you want the brim of your hat to be and make the width of the rectangle twice that width.
Step4
Place one wedge on top of another, right sides together. Make sure that the edges line up evenly. Use a sewing machine to stitch along one side, from point to base. Stitch 1/4 inch from the raw edges. Repeat with the two remaining wedges.
Step5
Place one hat half on top of the other, right sides together. Line up the edges evenly and stitch along each side, from point to base. Stitch 1/4 inch from the raw edges. Turn right side out.
Step6
Fold the fabric rectangle in half, right sides together, so that the short edges meet and line up evenly. Sew these edges together. Leave a 1/4-inch seam allowance.
Step7
Fold the band in half, wrong sides together, to create the brim of your hat. Use dressmaker pins to pin the band to the hat. The brim should lie inside the hat, and all raw edges should line up evenly.
Step8
Sew the brim into place and turn it up.
Tips & Warnings
Determine whether the fabric's width or length has the greater stretch to it. You should place the pattern template so that the width of the wedge has the greatest stretch. The length of your rectangle (brim) should also lie in this direction.
Add a tassel or pompom to the top of your hat if desired.
Reduce or enlarge the hat pieces as needed for a child's hat or an extra-large adult's hat.