Duco is a brand marketed by Imperial Chemical Industries (ICI now merged with Akzo Nobel) under which it sells its popular Automotive paints. Spray painting is a painting technique where a device sprays a coating (paint, ink, varnish, etc.) through the air onto a surface. The Duco brand represents a range of products meant for auto painting and refinishing. The topcoat or the finish coat available under the brand Duco is a Nitro Cellulose (NC) Lacquer. Due to its wide spread use and popularity, the name "Duco" has been genericized to refer to Nitro Cellulose (NC) Lacquers.
Duco was vastly popular as an automotive finish before the advent of Polyurethane paints. Now a days Duco has found a new life as a high quality finish for interiors and other architectural projects.
NC Lacquers typically are a clear or coloured wood/metal finish that dry by solvent evaporation and produce a hard, durable finish.