How about this?  I came across some professional fletcher's page that said he used nylon upholstery thread.  I got some last night and it is a tiny bit thick but very, very strong.  I'm doing a batch of 30 arrows right now so to save time I fletched with super glue (hold 30 seconds and repeat) and I'm wrapping my feathers with this nylon thread.  A drop of super glue spread around with the finger at the front and back keeps the thread from unwinding.
I fletched 18 arrows with a Jo-Jan mono fletcher while watching V For Vendeta.  Since I'm wrapping the feathers anyway, I like this super glue trick.  I would like to go on the record for recommending super glue, nylon thread, and V For Vendeta.
           J. D. Duff