The ability to create freehand sketches is an important skill for engineers and designers to acquire. The old joke about engineers and designers not being able to talk without a pencil in their hand is not far from the truth. Many design concepts and ideas are very difficult to express verbally, so they must be expressed visually. Sketches can be created quickly and used as a powerful aid in communicating technical ideas.
This chapter presents the fundamentals of freehand sketching as applied to technical situations. It includes both two-dimensional and three-dimensional sketching. Like any skill, freehand sketching is best learned by lots of practice.