As for plastic covering Ultracote all the way, but this is a very broad question. For different size, type, and construction of planes I use different covering materials.
Ultracote, Thermalspan, Koverall, and Fiberglass are my coverings of choice. For a gereric .40 size, non-scale aircraft I vote Ultracote.
ORIGINAL: Flying freak
I prefer monokote as i find it easier to work with than ultra cote, I burn wholes in ultra cote[:@]
- I have actually found the opposite when following the instructions that come with it... (Ultracote uses lower temps)
Monokote will hold bubbles and wrinkles, and also does not seem to shrink as much.