Our school concert is a mammoth affair and it takes over our performing and visual arts programme for a whole term. Each child works on his or her own costume and props. Part of my role is to help the art teachers design costumes or props that the kids can recreate. One act this year required wings - no problem ! However the wings had to be able to be hidden for part of the act and then we wanted a bit of a POW ! moment as the wings unfolded...so far so good until we were told the wings had to close again.
We played around with a huge variety of materials for this and spent ages working with dismembered umbrellas, the umbrella idea was great but we could get the wings to retract...
Eventually the laced X-ray wing was born. This wing is based on a fan design and I have to let you know that the genius of the X-rays was the art teachers idea.
Obviously I am not going to post the kids from school here, so here is Mr baggy-pants standing in. He is considerably larger than the kids these were made for but they are a kind of one-size-fits-all thing.
We started by joining X-rays together (sourced from the local vet and hospital) into a long rectangle which we cut diagonally. Each wing needs four but you could do more. The X-rays here are taped together but the kids used a hot glue gun.
We then framed each triangle back and front with bamboo strips (from an old window blind). Again this was done with hot glue.
Once dry we drilled a small through the bamboo at the pint of each triangle (actually I did this bit , we don't let the kids loose with the power tools)

We then put the four triangles together by placing a button between each one and wiring them. We used buttons because we had them but the effect here is really one of a washer. We need to separate the bamboo triangles enough so the don't catch on each other when they open and close. You could use cardboard or metal washers here instead.
Close off the loop and repeat for the other wing.

Into each wing, about halfway along, we drilled three holes. When laced up this creates the opening and closing mechanism. if you want your wings to close completely (as in only be as wide as one section , completely folding over each other) then you need your holes close together. The problem with that is , when open the triangles will tend to turn and you will get a "windmill' effect as each of the triangles angles open.

We then laced the wings together, tying off the plastic string at the beginning and end. We overlapped the wings, only the width of the bamboo.
To finish we simply wired the two loops together and added some elastic which is worn around the shoulders. The kids also covered the wire in black fabric so it didn't show against their black costumes. They also cut a design into the end of their wings. To open and close the kids simply grab them and raise their arms.

Back-lit on the stage we think they are going to look spectacular.
You know there would be a thousand ways to vary this. I think they would look good with the bamboo painted black as well and black string .
The kids have LOVED working on this project. For a start they loved the X-rays and had a ball trying to figure out what all the bones were, especially on the animal X-rays, they got to use hot glue guns and wire cutters - always a blast and they made something that actually works. We loved it because for the most part the kids could all the work , the only cost was glue gun sticks and the kids really enjoyed themselves.
Just for the record I wasted so many hours trying to figure out the configuration of that lacing method- I knew in theory that it would work but I just couldn't make it happen for the longest time so I decided I would make a tutorial and save the next librarian-come-concert-helper from the headache.