In the process of trying to skin some some thin, long foam wings. These are for a 104" U2 variant-the TR1. They are scale and therefore quite thin. One fellow suggested using Kevlar fishing line-as he had done-under the 'skins', drawn taut between ply ribs at each end. I was considering more or less convential spars, wood or carbon fiber rod/tube. The kevlar apparently has zero stretch. The question is: should wings of this type have the ability to flex, or are they best made as rigid as possible. The kevlar idea certainly has merit as to its ease of installation. Any thoughts? Bill