An Example of Cross Contours in Two Directions
Cross contour lines are drawn lines which travel, as the name suggests, across the form. Cross contours may be horizontal or vertical, as on the right side of the example, or both. Often, in more complex forms, cross-contours will be drawn at varying angles. In this rather lumpy example, the grid of cross-contours looks a bit like the gridlines on a globe or a diagram of a black hole in space.
Using Cross Contours in Hatching and Shading
Cross-contours are often used when hatching. The cross contour lines may be carried all the way around the form, or used in small sections, curved, or straight, as in this example. The angle of the hatching as it moves around the form changes according to perspective.
Even if you are using shading and attempting to create a smooth surface, being aware of the flow of cross-contours as you draw can help you create a shaded surface that follows and enhances the three-dimensional form, rather than fighting against it.