The brims are made of plastic rescued from the packaging for a dress shirt. Other possible sources are plastic spiral notebook covers (not the cardboard ones, though) or blister packaging if the product is big enough to have about 6" x 4" of flat (or gently curved) plastic. The smaller brim would probably fit on a plastic milk or juice jug.
The orange one has a zipper on the crown under which you can put any kind of Sekrit Surprize. The zipper was part of the neckline of the original shirt, which I cut to fit. I also like to put pockets on the crown, as I did with the brown one.
This tutorial shows the construction of the brown hat as I'd already made the orange one. However, the technique is almost exactly the same for both, just the pieces are slightly different sizes.
Step 1: Materials and tools
You can of course also use yardage. You need about 2 or 3 square feet for either hat, which is usually not more than 3/8 of a yard. One shirt would be plenty, I used two only because I wanted a contrast.
I suggest using a lining so you don't get bits of thread in your hair whenever you wear your hat. If you have enough, and it's not super heavy, you can probably use your main fabric. An old t-shirt works well too.
I mentioned the plastic for the brim in the intro. You need some of that.
Finally, you need about 4 or 5 feet of quilt binding, which is like very wide seam binding, an inch wide. It's available in packages of 3 yards in any fabric store. You can substitute another piece of fabric the same dimensions as the band, but I find quilt binding is easier and faster.
Finally finally, you need thread and a sewing machine. No special stitches are required, any old sewing machine will do.
Step 2: Prepare the pattern
Brown hat pattern:
Orange hat pattern:
The images could be improved, and maybe once I get better at using the GIMP I'll upload better ones but these will work fine if you enlarge them to the sizes marked.
Step 3: Cut out the pieces
Cut a brim out of your scrounged plastic material. The easiest way to do this is to trace the pattern with a sharpie and cut along those lines. Note that the brim piece does NOT include seam allowance, for this purpose.
Cut two of the brim pieces out of fabric. You will need to add 1/4 inch of seam allowance to these. I usually do this by tracing the plastic brim piece and then cutting 1/4 inch out from that. If your eye isn't that accurate (and I've been doing this for 25 years), do the tracing and then draw a second line 1/4 inch outside it and cut along that one.
I didn't add a pattern for the band because it is just a rectangle. Cut it by drawing and cutting a rectangle 1-1/2 inch wide and 23-1/2 inch long. This assumes your head is average size, which is about 22-23 inches. If your head is larger or smaller, adjust this accordingly, and leave about a half inch or so for hair and comfort. (Don't worry about trying to match the exact size of the crown piece edges multiplied by 6, or anything; you'll work this out when attaching the crown to the band as long as you've got the right general crown size.)
Optionally, cut a pocket piece. This needs to be a bit taller than the finished pocket as you'll be folding a bit over at the pocket edge. Look at the next step for how this is done and you'll see how to cut it.
Step 4: Optional Pocket
First, make a nice edge at the top of the pocket. Fold the top of the pocket piece back on itself, with the front of the fabric inside, about 1/2 or 3/4 inch. Sew each edge down at about a 1/4 inch in from the sides (pic 1 & 2).
Then turn just this bit inside-out, or really right-side out, so the edges are folded inside and the flap is on the wrong side of the fabric (pic 3 & 4). Stitch across the top to hold this flap down (pic 5).
I next ran a line of stitching around the round edge (pic 6), which I pulled on to gather it up a little and make it easier to get a clean curve at the pocket bottom. This is called a gathering thread. This would have been easier to do if I'd done it before making the top hem. (If you made a square pocket, ignore this bit.)
Next I pinned the pocket to one of the crown pieces, using the gathering thread to help me with the curve (pic 7), and stitched that down. And now the pocket is complete.
Step 5: Construct the lining
You may be tempted to stitch them together in pairs and have three fat pie slices, but resist that. Stitch two segments together, then add a third, for half a pie. At this point the temptation is to add a fourth segment (and then fifth, etc) but don't do that either. Stitch the last three together just like the first three, so that you have two half-pies.
You can then sew the final seam, which will now be one straight line. Trust me that you do not want to try to stitch the sixth piece of a pie in place around the point of it. Even the last third is difficult - going around points is just Hard and there's no need to do that here.
Step 6: Construct the crown
Now, put the crown and the lining together, with all the raw edges inside. Pin around the edges and run a line of stitching to hold the lining in place to the crown. It should be starting to look like a real hat now.
Step 7: Construct the brim
Turn the hat brim cover right-side out. You will now insert the plastic brim stiffening. You'll stretch the brim fabric a bit while doing this, and you'll want to pin the inside edges together as you go. This is to keep the plastic from coming out or shifting around while you get the rest of it in.
Start at one end, and slide the plastic in along the fabric, keeping it to one side of the seam allowances from the outer edge. Get the pointy bit of the plastic at approximately 1/4 inch inside the inner edge of the brim fabric. Again there is a line here to help out, but it's on the inside of the structure and harder to see. Put a pin through both the fabric pieces, as close to the edge of the plastic as you can (but not through the plastic). Now move an inch over, push the plastic in a bit more, and add another pin. Repeat until you reach the opposite side.
The pins need to run from left to right, assuming you're holding the brim with the raw edges up. For right-handers this is normal, but you lefties should make the effort to put the pins in 'backwards'. This is because sewing machines are all right-handed, and if the pins run the opposite direction you will not be able to get them out easily as you sew, as the presser foot will be in the way.
Once the brim is all pinned, stitch along your pin line to hold it together while you attach it to the rest of the hat. If your pins are in the right direction, you'll be able to easily take them out as you sew along the edge of the plastic, and the later you take the pins out the less shifting of the brim you will have.
Step 8: Attach the brim to the band
Next, sew the brim to the band. This is a bit tricky since you're sewing a straight piece (the edge of the band) to a curved piece (the brim), and the curved piece is not very flexible. Take it slow and feel through the fabric for the edges every couple of inches. Make sure you're not either a) sewing through the plastic brim stiffener or b) getting too near, or off, the edge of the seam allowance.
It's easier to do the seam if you put the brim underneath and the band on top, although it's a bit harder to see what you're doing.
Step 9: Line the band
Cut a piece an inch or so longer than the band, or just start at one end and cut it to size when you're done. Start at the center back, opposite the brim, on the same edge of the band that the brim is on (see the picture that illustrates this). Open out the binding and fold the end down about a quarter inch as in the first picture.
Stitch across the folded-down end and on around the band. Going over the brim is the only hard part, but since you stitched that down already it's not too bad. At the end, overlap your folded bit by half an inch or so and cut off the quilt binding. (And finish the stitching!)
Fold the binding under the band to the inside, pin, and stitch it in place (this seam isn't required, but it makes the final step of attaching the crown easier).
Step 10: Stitch the band to the crown
First, pin the crown to the band, outsides togehter. Ease or stretch a bit if they don't exactly match. It's fine if they're off a bit, I don't worry unless the band is bigger by more than about half an inch, or the crown is bigger by more than about an inch and a half. Just make sure the bigness is spread out evenly. Consider the placement of the pocket with reference to the brim, if you added a pocket.
Sew this seam together along the stitching line you just did.
Next, bind the raw edges using one last piece of quilt binding. The technique is very similar, start with an unfolded edge and fold the end down a quarter inch. Stitch all the way around over the fold, which should be on top of the old stitching line.
Now fold the loose piece of quilt binding over the raw edges and down to the inside of the hat. Make sure the other pre-folded fold is folded (how's that for clarity!). Pin if you are more comfortable with that, or just sew "in the ditch" of your last seam, making sure to catch in the folded edge underneath. This is called binding an edge, and it's hard to describe, so take a look at the pictures.