SMJmodeler
Hans: A good healthy discussion, I like that. I'm interested in discussing the term "band lines"...
Why, thankee, Owl..
What I mean by "band-lines" is the "color-bands" that're left between the the two shades of paint, for lack of a better term.... "Demarkation lines" is probably a more accurate term..
They're especially apparent of the sides of flat-turrets and on the hulls that're rather on the flat-side... I recall one issue of FSM that featured a build using that painting technique (sorry, don't remember who did it and when), and when the model was in one position it was fine, then when it was shot from another angle, the demarkation lines between the two shades was fairly easy to see.. At least, at close-up viewing, which is what judges do.. It might look great at four feet, but at four inches, you could have a problem..
That said, it's certainly a valid technique in some modeling situations where the lighting is fixed and focused (like a shadow-box), but once you lose control of the lighting, the appearance changes.. Another puzzle is the amount of contrast.. Getting the two shades paint to feather and smoothly blend aside, do you make the shade so subtle that it goes unnoticed, or do you plunge in and make a readily apparent transistion?
Personally, I don't know which.. I don't paint shadows on anything but figures because, as I mentioned, they're small, but I think the tank's big enough to cast it's own shadows with the available light and, as a result, change the shade (and the areas that are in shadow)...
Now, this isn't what I'd call a weathering technique, because it isn't... It doen't effect the shade or tint through fading, color-shifting, whether it's wet or dry, new or old paint, and/or the method in which it was applied (Factory or Field)..
While weather certainly does play a role in the appearance, because the weather affects the amount of available light, it's not a constant.. Painting "shadow" with a 2-D technique onto a 3-D object that can cast it's own shadows isn't a good idea unless you can control the "weather", IMHO... That's why I said I felt the technique was best left to shadow-box dioramas.. It's a permanent effect on a temporary angle otherwise..
Trying to paint "light effects" is best left to 2-D representations, as I see it... I think that modelers who are more "artist" than modeler have used the technique out of habit from painting on canvas rather than on a model, and generally, you see them do that kind of painting when photography is their primary means of display models to others, and it's kinda carried over into the world of "personal-viewing"...