I'm not sure if there's an American equivalent to Solartex.
Solartex is a heat-shrinkable textile with heat-activated glue on one side. It's a modelling equivalent of "Ceconite" as used on full sized planes. It's very tough and you can fill the weave with dope. It goes round corners better than most films. It's main drawback is weight. It is really heavy compared to normal films and I now only use it on open construction "Vintage style" models and then usually only on the wings. I covered a "Super 60" with Solartex after it had been covered with nylon, and the plane has never flown as well since.