>>7595095>wanted to give my unpainted kits a matte/flat finish, are there any alternatives to top coat?Melamine sponge, it is equivalent to 1000 +grit sandpaper. Use it wet, scrub in small circles. Daiso sells them.
As for spray painting, u can try your luck early in the morning (dew = lower absolute humidity). But what hobbyists usually do is to airbrush indoors with a vented spray booth.