A question you may have asked yourself. Does the finish on a ukulele affect the tone? And I thought long and hard whether to dip my toe into this pool..
The reason for my caution, is that this is one of those subjects that has plagued guitar forum discussions for years, and usually results in less than clear views and plenty of arguments on both sides. The discussions often become quite heated as people with their own views slug it out, but never really reach a conclusion. But as I thought about it for ukulele, there is actually a single very basic answer to this question, then that is followed by a longer answer that partially contradicts the simple answer. See what I mean?
Let's deal with the simple answer first - does the finish affect tone? Well yes, it does. It has to. Adding a finish on to a ukulele, particularly on the soundboard (which is the part of the ukulele that does most of the vibrating to create tone) must add mass to it and affect it. Of course how much it affects it, and whether it affects it for better or worse brings us on to the more longwinded answer... But yes, adding finish to a body of an instrument does affect tone insofar as it changes it.
So why do they add them? Well it's a mixture of changing the looks, particularly at the high end instruments, and a case of hiding a plain wood at the lower end, coupled with an overall level of protection no matter the price point. The difference between higher end finishes and those at the low end though is night and day. A luthier built instrument may use gloss to really make the wood grain pop, but a thick plastic paint finish used by the cheapest Chinese abomination is usually to hide the very unnactractive plywood beneath it.... In both cases though a gloss can provide much more protection to wood than a plain or oiled finish. It stands to reason.
But as I say those finishes can vary extremely widely. There is a world of difference between thick gloss paint, (or thick gloss varnish for that matter) at one end of the scale and a professionally applied and sanded back gloss on a higher instrument. Added to that there is a world of difference between gloss and a satin finish, or a hand rubbed oiled finish. Progressively, out of those options, whilst they are all finishes that cover bare wood, they tend get progressively thinner and lighter. I've discussed this topic with a luthier at one of the most well known Hawaiian Ukulele brands and they are of the view that their satin or oil rubbed instruments sound much more natural because the finish is so much thinner. If you think about it, Violins are almost never finished in high gloss for the same reason. Just his opinion of course, but when a top brand luthier tells you that, you kind of listen. He did, however, recognise that there are plenty of people who prefer a gloss finish, and in reality the difference was extremely subtle and subjective.
Now, the quality of the finish also has an awful lot to do with this impact. If gloss finishes were so bad, high end luthiers and ukulele brands wouldn't use them at all would they? Well, yes and no. Years ago gloss finishes were less common on ukuleles, and those that were available were a heavier form of nitrocellulose that could easily be applied too thickly. More often, vintage ukuleles are finished in either oil or a french polished shellac. Equally that is in part to do with facilities and the hassle involved in creating a spray booth gloss finish.. In fact, going back in time there are also some woeful guitars from some of the worlds very best brands that were made with massively thick gloss coatings that some say really muted the tone (and with age, started to yellow and crack). Things these days are quite different, and technologies like UV cured poly glosses, such as those used by Kanile'a can be applied extremly thinly, but still be extremely strong and glossy. Quite a difference to the older thicker glosses. So these days a good luthier can absolutely create a thin gloss that adds very little mass to the body of the instrument. But that costs because it takes time and a lot of effort. Sadly, at the other end of the scale, any fool can thickly apply gloss and make an instrument shiny, but in doing so, the finish is ultra thick and equally unattractive.
So as you can see we are starting to see the other complexities in finishes that mean that they are not all equal. And because they are not all equal, the answer to the question cannot be just as simple 'yes it does affect tone'. This brings us on to the second answer, which is that 'it depends on so many more variables'.
You see, no matter what the finish type, there are other things in play here which have a significant effect on the tone of an instrument such as the wood type, the quality of the tonewood, the quality and lightness of the build, the bracing pattern and many more. It's simply impossible to compare a gloss instrument to an oiled instrument and come to a fair view on what the finish is doing to them. In fact, I would wager that you couldn't fairly make a comparisong between two identical models, one satin and one gloss and point to the finish making a difference in the tone, as the woods in the instrument will be slightly different. Can you hear a difference in a side by side test like that? Well, yes youmay be able to, but what I am saying is that there still may be more subtle construction differences that are affecting things too. And of course, if that finish IS affecting the tone, whether it is affecting it for better or worse is purely subjective. Completely.
To sum up though, and hopefully provide you with the advice you were hoping to receive, I would say the following:
1. No matter the instrument, a heavier coating (whether gloss or paint) is going to reduce the top vibration. It just will.
2. On higher end instrument gloss finishes, this effect on vibration is likely to be much more minimal because the gloss tends to be applied professionally and very thinly. In fact, the effect may actually improve the tone to your ears! I do often hear people say that they prefer the sound of the gloss version to the satin, and vice versa.
3. On cheaper end instruments however, these glosses and paints tend to be applied overly thickly. With a lower end instrument, the construction build may already be overly heavy (thick laminates, heavy braces etc) and the last thing an instrument like that needs is yet more material affecting the vibration of the top. It's why on cheaper instruments I would almost always avoid gloss or heavy finishes. In short, if you are spending little on a ukulele, go for the plainer finish every time.
4. Ultimately though, the impact is completely subjective, and if you do like the look AND the sound, then it follows that you like the instrument. No matter what it is covered with. It's ok to like one or the other!
5. Don't however overlook the role that gloss can bring to protect a ukulele. Whilst gloss itself can scratch, from the action of fingernail strumming, belt buckles and zippers, it is usually just the gloss that is wearing. Trust me, as the owner of a high end, oiled finish ukulele, they DO pick up strumming marks directly into the wood more than gloss instruments do. Personally that doesn't bother me as the ukulele still works and such marks show that it has been loved. Some people though prefer to keep their instruments looking like museum pieces..
Oh and as a final point. Adding stickers or hand painting with acrylic all over your ukulele will CERTAINLY mute the sound. If you want to do it, go for your life, it's your ukulele... Just know the risks and try to bear that in mind when advising other people to do the same. Personally, I prefer a ukulele to resonate as freely as possible, not as little as possible.
© Barry Maz