There are many subjects that split opinion among guitarists. And believe it or not; guitar finish types is one of them. Although most players aren’t too concerned about the type of finish that’s been applied to their guitar, for some players and luthiers – it’s actually quite contentious.
Two main sides split this debate; those that favour old-school nitrocellulose lacquers, and those that are content with modern polyester and polyurethane finishes. Traditionalists find the former more appealing, as nitrocellulose was used almost exclusively on vintage instruments from the golden era of guitar production. But there are many guitarists that prefer poly finishes, as they are more resistant to wear and have a glossier look.
In this piece, we’re going to shed some light on these two types of guitar finish. Explaining their advantages and disadvantages, as well as the effect that they have on the sound of a guitar; we hope that by the end of this article you’ll have a greater understanding of their differences.
Nitro Guitar Finish
Nitrocellulose lacquers have been around for almost a century; originally used for acoustic instruments, saxophones and even cars. This finish later became a popular choice for Fender and Gibson in the ’50s and ’60s, who used it almost exclusively for their electric guitars. Fender also experimented with acrylic during this period, but nitrocellulose was generally favoured for finishing guitars as it could form a nicer gloss.
Regarding its content, nitrocellulose lacquer is mostly solvent-based and comprised of plant-based substances like cotton, mixed nitric and sulfuric acids. The nitrocellulose element serves as a binding agent, which is then mixed with solvent to enable a conventional spray finish. The solvent used is acetone; a highly-flammable substance that ultimately forms the shiny lacquer.
A nitrocellulose guitar finish is applied multiple times over several days, with each coat essentially melting the previous one. This process eliminates the need to sand between layers. After full application, the solvent chemicals are left to fully dissolve; leaving a dry resin-like texture. This is then hand-buffed and sanded until a glossy finish is achieved.
Pros & Cons of Nitro Guitar Finishes
Nitrocellulose is considered to be more porous than polyester or polyurethane, with a thin, smooth and somewhat slippery texture that isn’t quite as solid or constrictive. Many purists and luthiers therefore believe that a nitro finish allows a guitar’s wood to breathe, yielding a more open sound and greater sustain.
Although nitrocellulose lacquer may give a guitar an airier sound, its softer texture does make it susceptible to cosmetic damage. This means that dings and scratches are more visible on guitars with nitro finishes, and much easier to inflict. A nitrocellulose lacquer also wears away over time, causing dulling in areas where you make regular contact with your guitar; such as the lower bout where your forearm rests. Nitrocellulose also yellows with time, especially when exposed to excessive sunlight.
Apart from the above, small cracks can appear in a nitro finish after several years too. This occurs when a guitar is regularly exposed to differing temperatures, as changes in climate causes wood to expand and contract. And as we explained, nitrocellulose lacquer is thin and slightly porous, meaning that the wood it’s applied to is more prone to this issue.
Which Guitars Have Nitro Finishes?
These days, this type of guitar finish is used almost exclusively by Gibson and Fender’s Custom Shop divisions. As these departments mostly produce premium time-honoured instruments, they therefore use nitro finishes to recapture the essence of their older vintage models. Nitro lacquers are also typically used on more expensive guitars as the application process is time-consuming and requires several layers. They must also be carefully hand-buffed and sanded at the final stage to ensure a consistent, professional quality.
What’s interesting, though, is that a lot of high-end guitars are deliberately damaged and worn to create an aged look. In the industry, this is referred to as“relicing”; a practice that has become more common from the growing demand for older-looking guitars. As nitrocellulose is easy to damage and manipulate, most relic’d guitars you’ll come across will have this finish. Attempting to relic a poly-finished guitar would not look very convincing at all!