Automotive Paint is paint used on automobiles for both protective and decorative purposes. Water-based acrylic polyurethane enamel paint is currently the most widely used paint for reasons including reducing paint’s environmental impact.
Modern automobile paint is applied in several layers, with a total thickness of around 100 µm(0.1mm). Paint application requires preparation and primer steps to ensure proper application. A basecoat is applied after the primer paint is applied. Following this, a clearcoat of paint may be applied that forms a glossy and transparent coating. The clearcoat layer must be able to withstand UV light.
In the early days of the automobile industry, paint was applied manually and dried for weeks at room temperature because it was a single component paint that dried by solvent evaporation. As mass production of cars made the process untenable, paint began to be dried in ovens. Nowadays, two-component (catalyzed) paint is usually applied by robotic arms and cures in just a few hours either at room temperature or in heated booths.
Until several decades ago lead, chromium, and other heavy metals were used in automotive paint. Environmental laws have prohibited this, which has resulted in a move to water-based paints. Up to 85% of Lacquer paint can evaporate into the air, polluting the atmosphere. Enamel paint is better for the environment and replaced lacquer paint in the late 20th century. Water-based acrylic polyurethane enamels are now almost universally used as the basecoat with a clearcoat. -Wikipedia