One more thing. The way delineators do it is to put a thin dark line indicating a cast shadow from mullions and muntons. This is not accurate of course but it does make things pop. So if the muntons are relatively dark, the shadow would be darker and the stuff behind lighter to separate. The mullions would be the deepest and cast the longest shadow and the cast shadow would be darkest on the glass, the shadow on the muntons slightly lighter the muntons are not flush to the glass but almost so they would cast a very thin shadow and so on. I hope I make sense here. I am aware that how I think of things as a delineator and how reality is is not the same.