/ic/ - Artwork/Critique

>>2646140
I don't know if it has a name, that's what I need so I can study on it (if it has one).
Here's a pic, I should have posted an example in first place I'm sorry.
See the general light/shadow area is divided by an even darker line, which always seems to be very narrow.

It probably has to do with reflected light, but is it always narrow? Why isn't it there on the bottom of the cheek?

I generally understand that a nearby surface will bounce some light, but only for surfaces that are relatively close together / reflecting a ton of light, like the sky or a reflective floor.
I cannot understand why this darker line exists on the face of this drawing.

I've seen the same happen on legs, arms, stomach etc.