The Human visual system performs the task of reconstruction of 3D external world scenes from 2D retinal images. In this complex task, information about natural shading of the objects, which results from the interaction of light with the objects' surfaces, plays crucial role. In Marr's computational model of vision, shading facilitates the building of the primal sketch during the image-based processing phase as well as building the 2.5D sketch during the surface-based processing phase. Thus, shading figure among the most important visual cues. In depiction, which can be considered as inverse vision task, artificial shading does not necessarily mimic physical shading. Very often, artificial shading conveys also some stylistic or pure aesthetical information. Artificial shading may add to the depicted scenes more appropriate and stronger visual cues, thus helping to overcome the limitations of the media. Many skilled artists used such artificial shading in their traditional artwork by exploying various hatching techniques. In this section, we explore the spectrum of possibilities for artificial shading in computer-aided depiction. We describe some artistic shading and hatching techniques that have been proposed during the last 20 years in the field on NPR. We discuss the perspectives for future development of artificial shading in computer-aided depiction, adapted to emerging media.