The purpose of the coating can be decorative, functional, or both. We can perform all-over coating, completely covering the substrate, or only cover some parts.
Functional coating can be applied to change the surface properties for example: corrosion resistance, wear resistance, adhesion or wettability. Sometimes a coating can add a completely new property such as a magnetic response or electrical conductivity.
A major consideration for most coating processes is that the coating has to be applied at a controlled thickness. A number of different processes are in use to achieve this result, including special machinery while applying coatings and evaluating the quality. For ‘non-all-over’ coatings we control where the coating is applied.