This is where things get science-y. Young’s modulus of elasticity describes stress (density) over strain (the material moving and responding to stress) or more simply put—stiffness in an object. In a guitar, the wood and finish are coupled and since there’s a lot more wood than finish, the wood has greater effect on tone than paint. For an acoustic or hollow-body guitar the paint impacts tone more than it does on a solid body electric because the wood tops on these guitars are a lot thinner—roughly 1/10-inch thick as opposed to a 2-inch thick solid body.
Can Guitar Paint Affect Your Tone?
We asked Fender about the science of guitar paint and sound, and found that maybe the Smashing Pumpkins’ Billy Corgan was onto something when he claimed paint color affects tone.
By Henry Robertson Updated: Mar 5, 2019
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Does painting an electric guitar change the sound? It’s a question that’s been on the mind of the Smashing Pumpkins’ Billy Corgan, who’s been catching flak among gearheads on the internet for suggesting that paint color affects guitar tone. Corgan recently unveiled his signature model Reverend for Guitar Center, and said “I’ve found through the years that certain paints sound different, so the white Reverend, I think, sounds better.”
People who believe this idea typically talk about the type of finish used on a guitar, with nitrocellulose, polyester, and polyurethane being the three most popular. I buy into the notion that paint, like anything else you put on or in a guitar, will affect the tone, but I’ve found it difficult to get good answers on this topic, as a lot of the discourse is just forum talk full of speculation and contradictory answers.
To see if there’s credence to claims about guitar paint affecting tone, I talked to experts at the Fender Custom Shop and to Fender’s Senior Chemist Julio Cedano.
What Are Nitrocellulose Finish Guitars?
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The opinion of guitar snobs writ large is that nitro, the original finish electric guitar manufacturers used in the U.S, is better at preserving the natural resonance of the wood in a guitar than polyurethane and polyester. When Fender was getting its start, their guitars were painted with DuPont ‘Duco’ nitrocellulose lacquer and DuPont ‘Lucite’ acrylic lacquer—the same paints used on General Motors automobiles. You had your Lake Placid Blue, your Candy Apple Red, Olympic White, and so on.
The same as paint protecting the metal frame of a car from damage, the paint on a guitar protects it from dings, scratches, and weathering. But nitro finishes dull over time and the paint chips off. There wasn’t UV protection in the lacquer so you’d get a yellowing effect. Polyurethane and polyester were adopted among guitar manufacturers in the late 60s/ early 70s as a more durable solution to nitro. Unlike nitro, these finishes gave guitars shiny veneers that wouldn’t fade over time and they wouldn’t chip or scratch as easily.
But to a lot of tone purists, they choked resonance on the guitars. The true, rich dynamics and frequency ranges of the wood were dulled and thus a lot of people eschewed polyester and polyurethane and still do to this day.
Fender Custom Shop’s Master Builder Ron Thorn offers some historical context: “Polyester got a bad rap in the late 60s, 70s, primarily because it was applied very thick. Now you can spray it almost as thin as Nitro at this point. Film thickness is a big factor, more so than the material. Tonally, if you keep it thin, they’re going to be very similar.”
A More Refined Poly
Over time manufacturers improved how they applied polyester and polyurethane to guitars, and now it’s hard to say poly is inferior to nitro. If you love the vintage look—dings and all—and want to see the wood grain, go with nitro. If you prefer a glossier look and are really striving for durability, go with poly.
This is not to say poly and nitro produce no tonal differences. While Fender is naturally wary suggesting one finish they use sounds better than another, Cedano told that “laquer is more permeable and allows the wood to breathe and resonate more than the more durable polyester finish which can impinge a bit on resonance. It’s the balance of tone and durability.”
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A thing that nitro proponents always bring up is that nitro never stops curing. It’s the same thing with concrete. Scientifically speaking, the solvents are continuously dissolving from the film and the fatty globs or emulsions containing the resin, pigments, and coalescing agents are left interlocked and bond with the wood and unto themselves and flatten out and flow into a uniform film.
Put simply, the paint thins out over time (hence the cracks you see on nitro finishes) and theoretically the resonance and tone are continuously getting richer, no matter how infinitesimal. A guitar with a poly finish cures within days, so setting aside the myriad of other wear and tear variables and just focusing on paint, a poly guitar will sound the same two years into owning it as it did within the first two weeks.
How to Relic a Guitar – Guitar Relicing 101
You might not want to practice on a guitar you love, just in case it goes horribly wrong! You can pick up cheap second hand guitars at junk shops, antique emporia, charity shops or online and hone your skills before letting yourself loose on your favourite instrument.
Because the body material and the pickups remain the same, the sound of your guitar shouldn’t change. If it’s a cheap model, sadly it won’t sound any better. Upgrading the pickups to more ‘rustic’ or ‘vintage’ sounding ones will give your guitar the look and sound of a killer axe but is entirely optional. On the positive side, you won’t ruin the sound of a good quality guitar that just needs a touch up or adding your own customisation to it.
DIY Relic Guitars – Step 1 – Making the Wood Look Old
The guitar body, neck and the headstock are easy to age. Manufacturers do it by enhancing the varnish’s ‘fraying’, usually with a very fine grit sandpaper. It’s simple, but you need patience.
Where do you carry out the distressing? Natural wear occurs wherever the act of playing, storing or transporting the instrument causes damage. There are plenty of images online, or you could make a note of the effects your own style of playing has on various areas, for example:
- where your hand rests on the body
- where your fingers habitually rub the neck
- either side of the strings (although not below them)
- the lower part of the guitar, where your arm rests when strumming
- just below the pickups, where your pick wears the lacquer away
- around the control buttons
- on the neck, between the frets
Before you begin, take all the metal parts off and, if at all possible, remove the neck altogether.
Most instruments are coated with polyurethane lacquer, some are coated with nitrocellulose, which is thinner and helps the guitar resonate. You need to remove the varnish in the places you want to create wear. Both types of finish are sensitive to sunlight and temperature differences, so you can stand the body in sunlight after you’ve carefully sanded the surface. When it’s hot, cool it down as quickly as you can. A freezer is ideal if yours is big enough. Then repeat the process until the finish starts to crack.
Alternatively, simply heat the parts of the body you want to look old with a hair dryer then cool it fast with a compressed air spray. If you hear a crack, don’t worry. It mean the process is working as it should. Just bear in mind it’s a bad idea to do this with the neck attached because you might bend it, which could be potentially expensive to fix. Be wary of acoustic guitars where the neck is fixed, so you might want to skip this step when aging an acoustic guitar.
When you’re happy with the level of distressing, rub the instrument down with a damp cloth. While the un-lacquered parts will soon get grubby through natural wear as you play, you can use a dirty cloth to give the finish instant personality.
Creating a Road Worn Guitar – Step 2 – Distressing the Metal
You don’t have to distress the metal parts. But it goes a long way towards creating an authentic relic look. Firstly, remove them from the body. Then get busy creating damage. You can hit the parts with a brick or stone, or even concrete, to pit the surface and create a key for dirt to accumulate. Scratches are also good, exposing the metal underneath the shiny plated finish.
You can also rub the shine off with either a fine metal file, wet sandpaper or steel wool, check out our range of abrasives for more information on sanding and abrasive materials. If you want to take things further for a more dramatic look, you can dip them in bathroom cleaner, which is abrasive and often acid, and eats away the surface beautifully. Remember to check progress regularly so you don’t go too far. Twelve hours isn’t uncommon, so exercise patience. When it’s done, simply rinse the parts with soap and water.
