Poly vs. Nitro Guitar Finish – Does It Matter?

Ask any two bass players about nitrocellulose versus polyurethane finishes and you’ll often get a heated argument. The debate over which finish is better has been raging for over 40 years now. Fender, and other manufacturers, have used both over the years. And, as vintage collectors clash with modern techniques and sensibilities, we’re left asking if the poly vs. nitro guitar finish debate is even worth fighting anymore.

What is the poly vs. nitro guitar finish debate?

The nitrocellulose guitar finish argument

In one camp, the feeling is that nitro guitar finishes are better because they let the wood “breathe” and give the bass a more open, natural sound. They do this a couple of different ways.

First, nitrocellulose lacquer goes on very thin and basically melts into the previous coat as it dries. It takes several coats over several days to complete the nitro guitar finish, but it still ends up leaving a thinner, somewhat weaker finish than poly does. This is where a lot of the talk about a bass or a guitar being able to breathe after the application of a Fender nitro finish or any brand for that matter.

Also, a nitro guitar finish wears much more quickly and easily than a poly guitar finish does. It acquires cracks and worn areas that allow the wood to show through and, as some say, breathe. Whatever side you fall on with this debate, this last point is simply true. A nitro finish will most definitely wear and deteriorate much more rapidly than poly.

Support for finishing a guitar with polyurethane

The other camp will tell you that there’s absolutely no difference between nitro vs poly except that a poly guitar finish offers much better protection. They’ll say that the tone isn’t affected at all.

In terms of protection for your bass, they’d be right. A polyurethane finish is actually a lot more protective than nitro. First off, a poly guitar finish goes on much thicker. It creates a solid, heavy coat that seals in the wood of the body much more than nitro does.

Also, finishing a guitar with polyurethane creates a coating that wears and damages much more slowly than a nitro guitar finish. A poly guitar finish is like wrapping your bass or guitar in armor when compared to nitro. It doesn’t crack, yellow, or wear off nearly as fast.

The poly vs. nitro guitar finish sound difference

The interesting thing is that while you can find people on either side arguing vehemently that they can hear definite tonal differences between a nitro and a poly finish, there are many, many more who say they can’t. It’s a bit like people talking about wine. Maybe you can tell the difference between a $20 bottle of wine and a $50 bottle, but if you can you have an amazingly developed palate. Most people just can’t tell.

I’ve owned basses with both finishes, and currently, my two main axes have the nitrocellulose lacquer finish. So, do I notice any difference between nitro and poly? When I got my first nitro finished bass I thought I did hear a slightly more open and clearer tone. The question is, was I really hearing a difference, or was I imagining it?

Over the past few years, I’m starting to think that this was all sort of a placebo effect. When you want to hear a difference you will. I have played several poly finished basses lately and to be honest they sound the same to me as my nitro finished ones. Now maybe my ears aren’t as good as some other people or maybe I’m just not listening hard enough but I really can’t tell any discernible tone difference between the two finishes and I will bet that most others can’t either.

Some other notable poly vs. nitro finish differences

Just to point out a few other differences that might actually be more important to a buying decision, consider the following.

Environmental factors

Nitrocellulose lacquer finishes have been highly regulated now as they are considered high VOC and aren’t particularly friendly to the environment. You really only find it on higher-end instruments like Fender reissues and Custom Shop axes. The Fender nitro finish is something still very much sought after, and people will pay handsomely for a bass with a nitro finish.

Poly finishes, on the other hand, are considered relatively friendlier to the environment. This is in large part due to the type of solvent used in the finishing process.

Look and feel

The look and feel of a nitrocellulose lacquer vs polyurethane finish is probably the biggest, and most agreed upon difference after protection levels.

Nitro offers a softer, more natural and organic look and feel. The fact that it wears the way it does is possibly a contributing factor to how people “hear” it as well. It just looks worn in and comfortable over time.

Poly will offer you a solid, bright, polished look for years and years. You obviously need to care for your bass as much as possible, but polyurethane will keep a sharper look and feel for much longer than nitro.

The ugly truth about the poly vs. nitro guitar finish debate

The final “nail in the coffin” though is that since 1960 all Fender basses have been sealed with an undercoat known as Fullerplast. This sealer is essentially a urethane finish under the nitrocellulose top coat. So to my mind, only a Fender bass made earlier than 1959 could possibly have any sonic difference in tone regarding the finish.

Today Fender uses poly to seal all their wood bodies that get a nitrocellulose top finish. So basically when you buy a nitro-finished bass, you’re playing a poly/nitro bass. I know there are many bass players out there that swear that a nitrocellulose finish will sound better, especially when recorded.

I don’t know about that but one thing I do really like about nitro finishes is that they age faster than poly finishes. The older a nitro finish gets, the more beautiful it looks in my opinion. For some people, this is a reason to avoid nitro as it is much more fragile than polyurethane. I happen to love basses that show natural wear and tear so the more delicate nitro finish is a bonus for me.

My overall and final view on nitro vs. poly is that sound-wise it doesn’t matter. If you want to change your sound think about new bass strings, new pickups, or as a last resort a new bass. And if you do, poly or nitro…it’s your choice.

If you’d like to offer your thoughts or argue your side, let us know in the comments below.

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