NC Thinner or nitrocellulose thinner, is a type of solvent used to thin nitrocellulose-based paints and coatings. Nitrocellulose is a type of resin that is commonly used in lacquers, automotive paints, and wood finishes. NC thinner is designed to dissolve and thin nitrocellulose-based coatings to improve their flow and consistency for easier application. It is also used to clean up tools and equipment used in the application of these coatings.