Koverall isn’t an iron on covering. It is a light weight polyester fabric that is heat shrinkable. It is applied to the structure using dope or one of the full scale fabric adhesives such a Fab-Tac (or I have used Balsa Loc and ironed it on but it works better with the adhesives). The finished weight is comparable to the iron on plastic materials but it is a lot tougher and more puncture resistant. I am currently flying a .15 and a .10 powered plane as well as a Saito .80 powered biplane that are all covered with Koverall. It also doesn’t sag in hot or damp weather.

There is also a lighter weight non-woven material called Polyspan. It looks like the old silkspan but is heat shrinkable and much stronger. It must be attached with dope, etc. rather than ironed on. It is waterproof also and unaffected by the weather. It is suitable for smaller models from about .10 size down to .020. It is only available in white but takes dope real well.