Merideth, you're coming along nicely. Glad someone likes my engraving technique! It sure is a helluvallot easier than using diggers...
Anyhoo, you asked me about the panel lines on my Spitfire. They were all done with pastels, a mixture of black and browns. I chose that particular mix because it was an Aussie Spit, and they often times looked like they'd been through a war. (Wait, they were...) Anyhoo, I wanted to suggest a little dust/dirt with the browns.
And I never did answer on the flat finish...
My 'secret weapon' isn't all that exciting. I simply use tri-grit sanding sticks to sand-down my final coats of Future before adding a bit of flat. The dark gray part of the stick is great for sanding down clear coats to get rid of dust or other roughness in the finish. You just have to be careful not to sand through to the underlying paint or decals.
If you're using Future, put a buncha coats on before you sand. When you're done, just wipe off the sanding dust with a slightly damp rag. Here's the sticks I use:
I use only these these types of sticks for this purpose, but not all tri-grits are created equal.
They're somewhat expensive, but if you getcher hands on some
Squadron tri-grits, (the last two on the right) they're what you wanna use for this; and they're a good gauge for buying other similar sticks which are usually less expensive. (If you'd like I can send you one of mine...)
I've got several tri-grits that came from a number of sources, and some are way too rough for this technique. So if you're going to buy some of these at a drugstore or dollar store or whatever, compare them with the Squadron stick to make sure the grit of the dark gray area is similar.
Also, if you can't get a dead flat finish, that's not really a bad thing. Many aircraft had a slight sheen to the finish, even if the paint was technically flat. But in the end, it comes down to personal preference...
Fade to Black...