Lead naphthenate is primarily used as a drier in oil-based paints, varnishes, and printing inks. It accelerates the curing process by promoting the oxidation and polymerization of drying oils, helping the film form quickly and uniformly. This results in faster drying times and improved surface hardness. It is often blended with other metal naphthenates, such as cobalt or manganese, to enhance performance and reduce potential defects like wrinkling or surface tackiness. Due to its effectiveness, it has been widely used in industrial coatings and wood finishes. However, because of the toxicity of lead, its use has declined in favor of less hazardous alternatives in many consumer applications.