The tutorial presents state-of-the-art visualization techniques inspired by traditional technical and medical illustrations. Such techniques exploit the perception of the human visual system and provide effective visual abstractions to make the visualization clearly understandable. Visual emphasis and abstraction has been used for expressive presentation from prehistoric paintings to nowadays scientic and medical illustrations. Many of the expressive techniques used in art are adopted in computer graphics, and are denoted as illustrative or non-photorealistic rendering. Different stroke techniques, or brush properties express a particular level of abstraction. Feature emphasis or feature suppression is achieved by combining different abstraction levels in illustrative rendering.