Three-dimensional (3D) scanning processes have been applied to a wide range of manufacturing industries for inspection and reverse engineering. Especially, optical scanning method is used mostly as a non-contact scanning technique in manufacturing field. However, it can be influenced from surface characteristics such as transparency and reflectivity. To resolve these problems, various coating techniques have been studied for years. Among them, atomization-based coating method is one of the key technologies to change its characteristics before scanning the objects. In this study, atomizationbased spray coating system is developed for producing a uniform thin layer. Then, a series of experiments are conducted to evaluate the coating performance with the developed coating system. As a result, after coating the surface of transparent and shiny target objects: glass slide, colour sample, cell cover, and clutch lever, 3D scanning results show that a uniform coating of target objects is significantly improved. Its coating thickness is less than 1 μm which means that it is important to keep the geometry unchanged of the part.