RE: Solartex verses Coverite
If you are not painting SolarTex (or any of the "Tex's), I strongly suggest giving the finished airframe a coat of clear.
The clear coat does a couple of things.
1st, it seals the edges of any decals so fuel doesn't get under them.
2nd, it provides a smooth flowing finish with no demarkation lines where deals are
3rd, the weave of the Tex's is more open than Coverite. Because of this, it picks up dirt and grime easier. While this can be cleaned by scrubbing with a fingernail brush, I have found that light colors (white, yellow, etc) never seem to get as clean as I would like. The clear coat makes cleanup as easy as if you had a film covering.