What is this panel line technique called?

When I look at models of modern aircraft (or some World War 2 aircraft, even), I notice that a lot of modelers seem to employ a technique where not only panel lines are accented with a wash, but also seem to have sort of a darker airbrush spray around them. For instance, seanrgb’s signature picture:

Personally, I think the effect looks absolutely stunning, but I’m not sure of what exactly it is supposed to replicate in real life, and how to achieve it. I practiced using strokes from my airbrush on an old F-4 Phantom and it doesn’t seem too difficult, but are there any guides to doing it? How does this “weathering” (is it weathering, or are they actually painted like that?) effect occur in reality? Why is it only done on certain planes (I see it mostly on Navy F-4 Phantoms and F-14 Tomcats)?

Thanks, and Seanrgb, those are some excellent models!

Check this Master Cheng’s build up of Macross VF-0 (a sci-fi aircraft). He gives a really good explanation as to how he does panel lines like that. The build up thread is very long, but I’m telling you now this guy is a master and every bit of information he offers is worth looking at!

http://www.macrossworld.com/mwf/index.php?showtopic=5881

pre-shading with a very darker colour (eg black) or post-shading with a darker shade of your top-coat or a whethering colour

I think what you are talking about is called pre-shading. It involves spraying a dark colour (usually black) sprayed in fine lines along panel lines. This is then oversprayed with thin coats of the final colour of the plane until you get the depth of shading you want.

Some people also use post-shading which is just the opposite of pre shading. Spray the final colour and the spray a slightly darker mix of this colour along the panel lines. Usually followed with a thin coat of the final colour to tone the effect down a bit.

Hope this helps