How does solvent evaporation form a coating film?

In evaporation-based film formation, the polymer is fully developed—meaning its molecular weight and chemical properties are already established—before it is dissolved into a liquid coating along with pigments and additives.1

When this liquid mixture is applied to a substrate, the film forms exclusively through the evaporation of the solvent. As the solvent leaves the system, it leaves behind the solid coating material. This process is considered one of the simplest and fastest methods of film formation, historically utilized in products like nitrocellulose lacquers and many modern spray paints.1

However, because this method relies on large quantities of organic solvents, it releases significant amounts of volatile organic compounds (VOCs) into the atmosphere. Due to the role of these substances in contributing to air pollution, the use of pure evaporation-based coatings is now strictly regulated by environmental legislation.12