In honor of Halloween and because someone emailed me to ask, here's how I made these batwings for my costume...
I bought at least 6 yards of stretch velour fabric for the wings. I chose stretch velour since A) it doesn't really fray, B) it's soft and stretchy, C) it's fuzzy! Prewash and dry your fabric. Also get six thin three-foot dowel rods for the "bones", velcro to make wrist bracelets, and electrical tape to join the bones.
I folded the fabric in half, nice side inward, and drew my double-wing shape (as if the wings are outstretched) on that. I suggest making a full-size pattern of one wing to start, using the dowels to help you lay it out. I also suggest keeping the bones straight as shown in the sewing pattern above, not curved as they're usually drawn in cartoons...
I made sure the upper edge was the same length as my outstretched arms, wrist to wrist.
Once the outspread wing shape is drawn, pin it and then cut around the edge. You can sew it at this point, but cut a slit in the center as shown.
After sewing, you'll be able to turn it right side out again. Then you can put the wings on like a jacket.
At this point you should have big floppy bat wings! So far, so good!
Take them wings off again, leaving them right side out. Make two sets of three dowel rods, joining them at the top using the electrical tape.
Add velcro bracelets to each set of "bones" so they'll stay put by your wrists. Lay the wings out flat, front face up, and insert each set into the wings, and slide the "bones" into the points.
You may have to trim the dowels for length. You want the fabric to be just taut enough that the points don't flop around. Once you have them adjusted for length, temporarily remove the bones and use electrical tape to wrap the tips, so they'll be less likely to punch through the fabric.
Put the bones back inside, arranging them the way you expect they'll be... pin the fabric around them on both sides as shown by the dotted lines in diagram above.
Next, you sew... I found it easier to sew with the bones still inside the fabric. Sew up and down on both sides of the bones so they're in pockets. This keeps them in place. Be sure NOT to sew these pockets all the way up to the top, since you'll need room for your hands and arms. Also, a little leeway here will allow you to remove the bones later in case you'd like to launder your wings. :)
That's basically it! I hope this helps. If you try these directions, please let me know and send me a photo at firstname.lastname@example.org ... I'd appreciate it!
If I ever make this again, I'd sew in brown gloves for my hands so they'd be less obvious. I'd also experiment with making the innermost two bones on each side be jointed... it'd be a more natural look, and might make sitting easier.