A little more background on SLC covering:
It is polyester, .75 mil(.00075 in.) very light, over 20,000 sq.in./lb
It is fairly tear resistant, unlike some other films(polypropylene esp.) so a tear doesn't usually run away.
It has a fuel resistant adhesive on one side. It can be lifted up and repositioned at least twice, if needed.
Low temp, goes directly over foam. I use about 275 deg. on a Coverite iron. I can pretty easily form it around rounded off bare foam tips with no wrinkles(takes some practice, but is pretty easy even with just an iron)
The film is treated for paint adhesion. This treatment does have a shelf life, but for film that is rolled up it should be pretty much indefinite. Most people lightly buff the surface with green Scotchbright.
Make sure the film goes on without wrinkles on the flat surfaces. Any wrinkle is impossible to get out. Wrinkles around the tips and edges can be covered with silkspan and filler and sanded to cover up. But the stuff is incredibly stretchable, so it will go around most curves. Move the iron around and work it in stages so an already smooth area isn't reheated and pulled into a wrinkle.
Apply one coat of auto primer. You can use almost any kind. Rust-O-Leum Auto Primer is cheap and easy to apply. One thick coat, and then sand almost all of it off. If the edges are properly ironed down(by wiping the iron across the edge) one coat of primer will completey hide any seams.
Any other paint can go over the primer. Auto two part, Rust-O-Leum, even dope. Doug Moon has done several planes with auto paint and had excellent results.
You can apply silkspan or silk over SLC. Water-based polyurethane varnishes(Carver-Tripp, Varathane are fuel proof versions) or Min-Wax(not fuel proof). Dampen the silkspan lay it in place and work the varnish through it. Make sure all wrinkles are worked out as much as possible. A wrinkle in the middle of a panel will be VERY difficult to sand out. Wrinkles in the silkspan around the tips can be sanded and filled to make them disappear completely.
On a large stunter (700+ sq.in.) adds about two ounces for a layer of covering. One solid coat of paint adds the same. A complete finish, SLC, primer, base color, trim, will run 6-8 oz. no matter what paint is used. Adding a layer of silkspan adds another couiple of ounces.