Ok, I get the concept of pre-shading, but it seems like a waste of time and paint to pre-shade something and then it get’s lost when you do a wash on it, or am I just over thinking it?
Depends on how opaque your main paint is to allow the pre shade to show through,or how heavy your wash is to obscure it.
It depends what you are you pre shading for, aircraft panel lines,or shadows on armor. What look are you trying to achieve,once you know that,then you vary the intensity of your pre shading and how much your going to cover it to get the effect your trying to achieve.