A Brief History of Finishes on American Guitars, by Jeff Jewitt

Finishes used on fretted instruments like guitars, lutes, and violins play a key role in the performance and quality of the instrument. While there are countless debates on whether finishes detract or add to the sound quality, the main purpose of a finish is to protect the instrument and add to its aesthetic appeal. Without finish, a wooden instrument would react more quickly to changes in humidity and eventually self-destruct. Plus, a finish deepens the color of the wood, and adds depth and luster which makes it visually more appealing and more playable.