One of the preferred lacquers in guitar making is Nitrocellulose Lacquers. It is one of the more safe lacquers to use compared to the catalyzed lacquers that often contain formaldehyde which are banned in most first world countries. The advantage of nitrocellulose lacquers is that when you apply your layers, there is a chemical bond between coats. If some damage occurs to the finish at some stage, it is easier to repair compared to catalyzed lacquers, in that, the layer can be softened with a solvent, whereas the catalyzed cannot. Nitrocellulose can also be rubbed with a pad like the French Polishing technique to help close the grain of the wood and to help create a fine finish. Below is some more detailed information specific to Nitrocellulose......
Lacquer is a clear or coloured wood finish that dries by solvent evaporation or a curing process that produces a hard, durable finish. This finish can be of any sheen level from ultra matte to high gloss, and it can be further polished as required. It is also used for "lacquer paint", which typically is a paint that dries to a more than usually hard and smooth surface.
Quick-drying solvent-based lacquers that contain nitrocellulose a resin obtained from the nitration of cotton and other cellulostic materials, were developed in the early 1920s, and extensively used in the automobile industry for 30 years. Prior to their introduction, mass-produced automotive finishes were limited in colour, with Japan Black being the fastest drying and thus most popular. General Motors Oakland automobile brand automobile was the first (1923) to introduce one of the new fast drying nitrocelluous lacquers, a bright blue, produced by DuPont under their Duco tradename.
These lacquers are also used on wooden products, furniture primarily, and on musical instruments and other objects. Nitrocellulose lacquers are also used to make firework fuse waterproof. The nitrocellulose and other resins and plasticizers are dissolved in the solvent, and each coat of lacquer dissolves some of the previous coat. These lacquers were a huge improvement over earlier automobile and furniture finishes, both in ease of application and in colour retention. The preferred method of applying quick-drying lacquers is by spraying, and the development of nitrocellulose lacquers led to the first extensive use of spray guns. Nitrocellulose lacquers produce a hard yet flexible, durable finish that can be polished to a high sheen. Drawbacks of these lacquers include the hazardous nature of the solvent, which is flammable and toxic, and the hazards of nitrocellulose in the manufacturing process. Lacquer grade of soluble nitrocellulose is closely related to the more highly nitrated form which is used to make explosives. They become relatively non-toxic after approximately a month since at this point, the lacquer has evaporated most of the solvents used in its production.