You can make it reversible too (see the end of the how-to)! This project seems like it has a lot of steps, but I've broken it down a lot to make it easier to understand and correlate in pictures. I have high hopes for this; I will probably make more, sillier versions in the future.
Please disregard the puffy edges of the top of my hat, that was an error caused by making my pattern too wide. I overestimated the width of the top of my head I suppose. But if you adjust the way you cut the fabric or make the pattern, you can get hats in all sorts of fun shapes!
Measure the circumference of the head youâ€™re making the hat for, on or just above eyebrows is what I used. My measurement was 25â€. Write down that length. For these purposes Iâ€™ll call this measurement A.
-Divide that in half, 25/2 = 12.5 â€“ add an inch or two depending on the seam allowance or roominess you want your hat to have. This becomes measurement B. We'll need this for later.
Measure from your eyebrows/wherever you measured your circumference from to the top (highest point) of your head. It might help to stand in front of a mirror and turn your head more sideways to see better where the top of your skull is. Mine is 8â€, measurement C. If for aesthetic or comfort reasons you want a hat with a rolled-up brim like most winter hats, you can add two inches or so to this measurement.
If you have a large sheet of paper, or if you tape two sheets together, you will have something to make a paper pattern on if you like, so you can make more hats later skipping the first two steps. (See step 8 for an alternative to this method.) I have a desk calendar that I donâ€™t use and never bothered to tear the old months off of, so November became the pattern for this. Otherwise, it helps to use graph paper so you can cut a straight edge.
Make a line or mark the start and end of measurement B using a ruler or your tape measure as a guide. If you use the edge of your paper you can get a perfectly straight line (if your paper is in good condition, which mine was not)!
At about the midpoint of this line, lay your measuring tape (or substitute for a ruler if you want to make an actual line) perpendicular to your B-line, forming an upside-down "T". Mark off the length of your measurement C (8" for me). In the image I've circled each of the two marks in red to make them easier to see.
Another, better view of the measurements. Here you can see the T-shape idea a bit better.
Draw a curved line from each B-endpoint inward to the top end of your C mark. Your lines should start out fairly straight, and then curve them as they reach the top. If you're worried about getting the position of the curve right, you can draw a right angle with your ruler along the end of B and lying flat on your original C mark to give you a reference.
It doesn't matter if your curves aren't exactly even YET, it's best to make curves that are too big for what we want to start out with. When you cut it out, which you should do now, you can fold it in half and make sure they match up. This way, the edges of your both your cloth pieces will match perfectly. (This is more important for people like me who get a little confused by sewing something that has what seems like a larger seam allowance on one side. It also makes it easier to tell if your pieces have shifted while you're sewing it, because it's important that they match up so the rim of your hat won't be in two different places once you sew the pieces together.)
Another nifty thing to do is use a hat that you already own similar to the one you're making as a reference. But keep in mind that your reference is sewn together already, if you just trace it it'll be too small because it doesn't account for seam allowances.
ALTERNATE FOR STEPS 3-6: Cut out a rectangle of fabric with the dimentions of your B and C measurements and round off the top two edges, then trace that to make your pattern. I have a finite amount of shirts that I am willing to give up for other projects, so making the pattern first helped me save on making mistakes. Paper is more replaceable than a piece of fabric you've already cut.
Using a fabric pen or washable marker (it doesn't really matter because most t-shirt fabrics are very resilient against marker) trace your pattern on your shirt. If your shirt hasn't been cut up or used beforehand, you can save a step by lining up the bottom hem with your B-line; that way, you won't have to sew the hem yourself! Saves time. If you don't have that luxury, after tracing only the C-curves shift your pattern down about an inch to create a seam allowance, then trace the B-line (make sure the ends match up with the curves!)
Make sure the shirt doesn't shift beneath the pattern while you're tracing it! Double-check before you cut it out. If it helps, you can have an ironing board or similar flat surface "wear" your shirt to keep it flat and sturdy while you trace(and you can also iron it while it's there!).
Trace another hat-half in the same way and cut them out!
Lay your hat-halves against each other like a sandwitch, so that the right sides of the seams are together. To see what I mean by "right" and "wrong" sides, consult the picture for this step by clicking on it to see the red text. Line them up neatly and pin them together throughout.
Now, sew them together using whatever method you like! Because I wanted a sturdier hat (and also because I wasn't sure how the prototype would fit, I wanted it to have strong seams in case it had to stretch a lot to fit over my big fat head), I used my sewing machine.
Turn it right-side out, and you're done! You can decorate it however you like.
If you're making a reversible hat like I did, you should probably decorate this side now if you intend to do so. Unfortunately I skipped this step because I was so eager to see the final product, and now I have a hat that's really hard to decorate with anything that has to be sewn on. ): So keep that in mind! Here are some decorative ideas:
-Tassles, pom-poms, or ear flaps
-buttons, sewn on or the pinned kind
-Ribbons, bows, or lace accents
-painted or embroidered designs
For a reversible hat, sew another hat base and decorate as desired! Not only does this mean you can have one hat in two different colors, but it also makes it warmer (two layers!). But this time, don't turn it right-side out! With the seams showing, put your second hat inside of the first, which SHOULD be right-side out. Line up the rims, as shown, so they're even. To keep them even, pin them together.
Sew them together! If you like, you can use the rim's first seams as a guide.
Done! You can turn it to the other side and see how it looks, or test out different styles. The fabric layers should stick to each other on their own, so you don't need to sew them together at the top unless you want to. Enjoy your new hat!