@citizen lambda: May I ask what you mean with 'relief shading'? As English is not my native language I'm not familiar with this term.
OK, I really have to stop using that term, you're the second to ask in as many threads on the same day...
This is just about the lighter/darker shades being used to highlight the relative angles of the canted surfaces. For a baseline tone on a flat (facing the eye) surface, other surfaces tilted towards the light look lighter, and surfaces tilted away from the light look darker. Nothing fancy or original on SB, I just use "relief shading" as a shortcut (up to now). This is used everywhere on ships (see all modern ships with oblique superstructure sides) but I don't know how prevalent it is on planes.
_________________Soviet Century/Cold War 2020 Alternate Universe
: Soviet and other Cold War designs 1990-2020.