If the plane is fully sheeted, you can sand it, then you can use 3/4 oz fiberglass cloth and epoxy to "glass" it, then paint the fiberglass. You could also just paint the sheeting directly, but it won't be as strong. This will probably be a little heavier than just straight monokote. You'll need to make sure you use fuel proof paint.

If its not fully sheeted, there's the old school method of "silk and dope", but if you thought monokote was hard....!

Try using Ultracote. I've never used it since my LHS only carries Monokote, but those that use it claim its easier to work with.

For me, Monokote has taken some time to learn, and each job has turned out better than the last. Monokote is also pretty durable, and I like being able to use Windex to stick down stripes and other details, so I'll probably stick with it.

Brad