Automotive coatings and the processes used to coat automobile surfaces exemplify the avant-garde of technologies that are capable of producing durable surfaces, exceeding customers’ expectations of appearance, maximizing efficiency, and meeting environmental regulations. These accomplishments are rooted in 100 years of experience, trial-and-error approaches, technique and technology advancements, and theoretical assessments. Because of advancements directed at understanding the how, why, when, and where of automobile coatings, the progress in controlling droplets and their deposition attributes, and the development of new technologies and paint chemistries, a comprehensive and up-to-date review of automobile coatings and coating technologies was considered to be of value to industrial practitioners and researchers. Overall, the critical performance factors driving the development and use of advanced automotive coatings and coating technologies are (a) aesthetic characteristics; (b) corrosion protection; (c) mass production; (d) cost and environmental requirements; and (e) appearance and durability. Although the relative importance of each of these factors is debatable, the perfection of any one at the expense of another would be unacceptable. Hence, new developments in automotive coatings are described and discussed in the following review, and then related to improvements in production technologies and paints. Modern automotive coating procedures are also discussed in detail. Finally, an extrapolation into the future of automotive coating is offered with a view of the developments and technologies needed for an increasingly efficient and more sustainable coatings industry.

Automotive spray painting is among the most sophisticated and controlled industrial painting operations currently performed. Nevertheless, improvements in it are still sought in efforts to minimize the costs, the energy use and the environmental impacts. One compelling aspect of improvement is the paint transfer efficiency, i.e. the amount of paint that remains on a vehicle relative to the amount supplied to the paint applicator during coating operations, because currently it has been estimated that the overall paint transfer efficiency in the automotive industry is between 50% and 60%. Hence, this review assesses current automotive spray coating technologies with respect to their transfer efficiencies and discusses the fundamental and operational parameters that influence it. A comprehensive characterization of paint spray applicators (air sprayers, high-volume low-pressure sprayers, airless sprayers, air-assisted airless sprayers, rotary bell atomizers, electrostatic sprayers, and effervescent atomizers) is included. Some problems associated with evaluating and improving their paint transfer efficiencies are discussed. Also, the potential of and the technology needs for developing these applicators are considered.