The textures of some objects can be particularly challenging due to movement (water), fine detail (skin surface and hair, grass, leaves) or their ethereal quality (cloud, glass).
The texture in a drawing is also a product of the support, such as paper or canvas. Some papers, particularly those for pastel and watercolor, have a textured surface due to the fibres or the mold used to make the paper. Different mediums will show up the inherent texture in the paper.
As well as creating the illusion of texture in drawing, artists often use the inherent qualities of a medium combined with various forms of mark-making, such as rough shading, smooth blending, hatching or scumbling, to create interest within an image.