Undercoats

• Undercoats are a specialized type of auto body paint formulated to protect the car's metal. Also called primer, undercoats provide an adhesion surface for layers of basecoat color paint. Automotive paint will not properly stick to bare, unpainted metal. Red oxide and zinc phosphate are the traditional undercoat standards. Recently developed specialized primer paints include two-part epoxy primers, self-etching primers and enamel primers. Lacquer primers have been replaced by more durable urethane primers.
  
  

Enamel

• Vintage automotive paints are known as single-stage topcoats, monocoats, or direct gloss paints. Alkyd enamel was one of the first automotive paints devised. It is composed of natural polymers and slowly cures to variable gloss finish levels. While not required, activators may be added to improve durability. Acrylic enamel paints contain artificial acrylic polymers to speed up drying time and harden the car's finish.
  
  

Lacquer

• Car restorers use lacquer paints primarily to restore the original period appearance of an older car. Nitrocellulose lacquer, or NC lacquer, was invented to overcome the limitations of slow-drying enamels. NC lacquer is based on organic cellulose compounds derived from wood. Extreme flammability and yellowing caused NC lacquer to fall out of favor. Acrylic lacquer replaced NC lacquer with its increased durability and faster drying time. It's one of the cheapest paints on the market.
  
  

Urethane

• Urethane or polyurethane paints are known as two-part paints because they require the use of an activator to properly cure. Urethanes are the most durable kind of single-stage automotive paint. Isocyanate compounds used in urethane paint make them highly toxic and dangerous to use. Urethane paints are expensive, but produce a durable, shiny finish. They may be used with a clear coat for added protection. Tiny flakes of aluminum added to urethane paints produce metallic and pearlescent effects.