The Quick and Dirty Details on Guitar Finishes

Possibly the oldest decorative coatings are red and black lacquers from China that date back thousands of years. Chinese lacquer was primarily used to beautify luxury goods. Early lacquers were made from tree sap mixed with other organic ingredients for color and stability.

Shellac, made from the sticky secretions of the tiny lac insect, appeared in Asia and India around 1200 BCE. In the 17th century, shellac became popular in Europe among furniture and instrument makers. (Fun fact: It can take up to 90,000 insects to produce one pound of shellac.)

The word “lacquer” is a catch-all term for coatings made from resins, including tree pulp, sap, and chemically manufactured synthetics. These resins can be diluted with solvents, but not water. However, there is now a class of water-soluble finishes that are referred to as waterborne lacquer. Confusing, isn’t it?

For practical purposes, let’s divide coatings into two groups: thermoplastic, which cures by drying (solvent evaporation), and thermoset, which cures by a chemical reaction alone. All of these finishes are diluted with solvent in order to allow them to be sprayed or applied by a brush. A thermoplastic coating will release the carrier solvents over time, leaving the solid material behind. This can take from a few days to several weeks depending on the lacquer’s particular formulation and the temperature and humidity of the paint room.