The skull was drawn as a test of a small set of round brushes, I was curious to see how it would feel to paint with non-textured brushes (usually use texture brushes). I really like the look of drawings made with brushes like these, they are so smooth and neat.

For this one, I did a comparison of the effect of a rough painterly style with vivid colours and a black and white version with soft lines. My favourite is B/W

and one more:
