For some stupid reason whenever I start painting with pencil tool it simply doesn't act as expected at all. For example, I want to create a darkened shading effect on a base of one colour (skin colour in this case). Instead it draws a line with pale shade! Even worse, I cannot seem to draw other shades on other colours, like white - it just doesn't respond (although I can undo it, which still does nothing)! The fill tool still works properly.
Please help. everything worked fine with other projects, but on this picture it is just infuriating.