This. I see a lot of people looking for filters to get 'hand-painted' textures. The best way to learn is to roll up your sleeves and slog through the pixels.
It's because the DX11 renderer turns negative pixel colors into that. You can just make a postprocess material that clamps the min value to 0 and add it to your PPChain.
You are way overthinking this. Zoom out to a 'game view' distance. I bet those details drop down to not even be represented by more then 1 or 2 pixels.
Zoom in and do the deed then zoom out Working on detail the size of your finger would be awesome, especially when you zoom out and the line is pixel sized
DF2012 + new NVIDIA drivers = pixels on fucking fire, yeah! even had to go into the .ini and cap the FPS at 100 for fear that I was gonna throw a serif.