What is the main purpose of using cross-hatching in a sketch?

The main purpose of using cross-hatching in a sketch is to show construction materials. Cross-hatching involves drawing parallel lines that intersect at various angles to create a pattern, which can effectively indicate different types of materials used in a drawing. For instance, different patterns can represent wood, concrete, metal, or other construction materials, thereby providing clarity about what is depicted in the sketch. This technique is especially useful in architectural and engineering drawings where distinguishing materials at a glance can significantly aid in interpretation and understanding of a design.

While dimensions and shading are essential components of sketches, they are typically represented through other means, such as numerical notation for dimensions or different shading techniques for illustrating depth and form. Therefore, cross-hatching's primary role is firmly rooted in material representation.