Sorry not sure what you mean? Do you mean like when a person takes a street sign (like a stop sign) and attaches string to it and then flies it like a kite. I've done this (though it didn't' fly well or for long) and it has to be very windy for it to work.
I'd love to see a picture of this. But I agree with dd3stp233: What do you mean about "flying signs"? Are you talking about the peace sign with fingers? Or signs that are on paper and cardboard?
