Is there a blending mode that does this:


The opposite of what it's over? And extra, is there a blending mode that does exactly that but maybe you can control the hsv to make it non colored just white where it's dark and black where it's light?

You can get this behaviour using Binary -> IMPLICATION blending mode and using a black color to paint over it. Not sure about colors; probably won't work. Also it's not really a good usage of blending mode; you're basically asking to ignore the color you're painting with.

What is the usecase of this? Won't it be better to just create a filter layer (or mask) with "Invert" filter and paint on it with black and white to select the areas that the filter will apply to?

Well I'm working on a painting, and I turned out the sketch layer and thought, maybe I should actually use a little outline to accentuate what I'm doing, but then I thought what would give it an even more polished (like more thought put into it) is if I could have the light parts have dark outline and the dark parts have a light outline that even matches some of the tones of the painting.

And it could be useful if you are painting something on a very half and half background where you could see the dark outline for the light parts that lie in the light, and have lighter to both see and get you started in the shadow part.

Wow, Implication at first glance seems to nail what I was trying to do. I'm going to try to find out if I can simulate having a mixture of this and overlay possibly.