Hillbilly has the right answer. BUT, I did once fletch a dozen arrows with the right handed Arizona Fletcher and used all left wings. Didn't realize it until I was on the last arrow, beer and Ducco Cement don't mix, ya know.
Funny thing, though. They all flew pretty good...but then the jig put plenty of helical into the fletching, so they grabbed air and did the job.
Then, being the contrary sorta fellow I am, I grabbed an old shaft in the shop and mixed right wing and left wing and jammed them into the fletching jig, glued them up, fixed a field point on it and shot the goofy thing. My conclusion was that it was not worth walking out into the field to retrieve that object (note I did not call it an arrow).
Dull side of the feather is the underside, and on the downstroke of a bird's wing they need the most strength and this is the side that provides the most resistance to the wind. I have seen two fletch that used both sides of the same wing feather. But one side is going to do more work and the other side is going to flex more and carry less of the load. I imagine this could cause some unsteadiness in flight. I would think using two right wing feathers to make the two fletch would make for a much better flight.
