What is it about an engineered product which appeals to a potential customer at first sight? It is arguably true that shape and surface appearance are persuasive factors, even for products outside the consumer goods industry. While any customer, be he private or industrial, will purchase an item primarily for his expectations of its technical performance, nevertheless, much of the joy of ownership lies in the outer surface features. An obvious example here is a motor car for which, to the uninitiated, the difference between a desirable car and a run-of-the-mill vehicle is often only signalled by differences in shape, surface gloss, choice of colour and general decor. The designer of engineered products is, of course, aware of this, and should not be beguiled by subjective considerations, but nevertheless may find he lacks a general overview of finishes and coatings as protective systems with which to enhance his brainchildren. This chapter does not claim to offer a comprehensive treatment, but will discuss the more important aspects of surface finishing of which the designer should be aware. So the purpose of a finish is to be decorative, functional or to permit repair of a worn surface.

Surface finishing should properly be considered as a process of applying a system to a surface in need of treatment. The common belief that surface finishing is confined to cleaning a surface and applying a coat of colour is very far from the truth in the modern world.