I have used both Solartex and Ultracote cut to shape and ironed on for trim on Solartex. Both worked quite well though you have to be careful not to overheat them or they will shrink out of the desired shape. You need your iron set so the adhesive activates but so the material doesn't shrink. These temperatures are clearly outlined in both the Solartex and Ultracote instructions.

The Ultracote trim probably works the best and looks very good on Solartex. Very realistic actually as even older fabric covered full scale planes that didn't have a lot of gloss on the major part of the covering showed more gloss on the trim areas as there was more dope / paint build up there. You can also lightly buff the trim with very fine steel wool or a fine Scotchbrite pad to reduce the gloss.