The polymer is the continuous phase, or main part, of the coating and is responsible for the integrity of the coating. The polymer can be hard or soft depending on its composition and glass transition temperature . Control of polymer structure allows variation in polymer properties, thus varying coating performance. The pigments are used to hide and give color to the substrate. Pigments are either organic or inorganic fillers that are added to the polymer and solvents after the polymer has been synthesized.
Additives are the smallest portion of the overall coating, but can have the largest impact.
One usually thinks of a coating formulation in terms of its major components such as pigment, resin, and solvent. However, a coating simply will not work without a number of key coating additives that must be used. A component that is used in some occasions is a solvent. Solvents were originally used in all coatings, but with emergence of environmental legislation solvents have been reduced and in some cases eliminated. Solvents are used to reduce the viscosity of the coating enabling the coating to flow like a liquid and they can be applied by brush, roller, spray gun, etc.