Actually. paint does stick to mylar films just great. But first you have to scuff the film with a scotch brite pad or maybe some 600. The problem is:..........when the film sags, and sooner or later it will, you can't put an iron on it.

If you only paint small areas, then generally you can iron arond the painted portions and remove the sag. I have even placed a T-shirt over the painted areas and quickly run an iron over them. It did leave a little lint.

IF you draw panel lines on the film, and then try to shoot Lusterkote over them, often the Lusterkote's solvent will cause the lines to blurr and run.

So you are asking the same question that many of us are asking. How do you get good panel lines to stay on film.

As for a mat finish, well Monokote is making camo colors with a flat finish now. They look pretty good. You might be able to achieve a reasonable finish by simply scuffing up the existing covering with a scotch brite pad or similar.

Here is an Ercoupe covered with Monokote. The panel lines are really just areas that haven't been scuffed. The rivets were ironed on using a soldering iron and brass tubing. The pic is bad, but silver is difficult to photograph.