Martin Wood Grading

A reader asks for specifics about Martin wood grading.

I’ve seen it written “higher grade rosewood and spruce. But Martin does their grading solely on looks” on your website and other places. 

How do you know this is the what Martin does? How many grades of wood does Martin use?

Does it start with the Road Series being the lowest grade, then 16 series is next, then 18/28, then 35, and the 40+ gets the top grade of woods?

I read somewhere that the HD-28 had a better top than a D-28. is that correct?

Spoon writes:

It is true Martin only grades wood based on how it looks. However, the debate will remain forever as to whether visual appearance can accurately suggest what a piece of wood will sound like once it is on a guitar.

There are many who believe that perfectly quartersawn wood is not only a safer bet when it comes to long-term strength and stability, but that it is also more resonant or simply “sounds better” than flat sawn wood. Others dismiss such claims based on their own experience. And the same can be said for other visual clues from cross silking, bearclaw or haselfichte markings in spruce, to quilting and other exotic figuring in tonewood like mahogany or maple.

When it comes to customer orders at Martin, for instance from the Custom Shop, wood like Madagascar rosewood used for back and sides or Adirondack spruce used for tops, receives a designation of either “Standard” or “Premium.”

According to one veteran employee deep in Martin wood lore, “Premium means we sort through all the available 7 – 8 tops to pick out the best.”

A number grade like 7 or 8 is part of the internal grading system. There are usually two grades of wood for back and sides, and eight grades for spruce tops.

This is based entirely on what the grader decides looks the best, cosmetically. It is not at all about visual clues relating to sound. Anything like grains per inch, and so on, was already a moot point, since no wood gets to this grading stage that wasn’t already deemed within acceptable specifications to be used on a Martin guitar.

As for how they grade, someone stands in front of a long table stacked with recently milled wood and segregates them into the various grades, based on grain and coloring. They have examples on the wall in front of the table with suggestions of what to look for, both in terms of good things and bad things.

Martin Wood Grading
Wood Grading Station at Martin Factory

Back and sides of Indian rosewood for dreadnoughts is graded as either D2 or D4. Sides are graded in a similar fashion and matched to the backs, based on overall aesthetics.

Grading of spruce tops is more involved. There are always exceptions at Martin, especially when it comes to limited edition models, and so forth. But when it comes to the main series of Martin guitars, the grading works like this:

All “styles” have rosewood back and sides and spruce tops, except where noted.

Grade 8 – Style 45, which has abalone pearl trim around all edges of the top, back and sides, and sound hole rosette.

Grade 7 – Style 42 and 41, which have abalone trim around the top and rosette only.

Grade 5-6 – Style 28 through Style 40, various non-pearl trim, with Style 40 having a pearl rosette.

Grade 3-4 – Style 21 and 18, Style 21 is the lowest priced rosewood style, Style 18 has mahogany back and sides.

This is the case for all Martin guitar series like the Standard, Vintage, GE/Marquis, Authentic series. The various species of spruce are graded the same way, but prices vary. Grade 5-6 Adirondack spruce costs about as much as Grade 8 Sitka spruce, for example.

Until a few years ago, the grade of a top was written on the underside and was often visible inside the finished instrument, with the help of an inspection mirror and flashlight. That is why some people speak with authority as to the grade of spruce on a particular Martin.

Today the top is marked with a “shop number,” and usually outside of the pattern, so it is not included in the finished guitar. A shop number is a production order number. Every shop number generally consists of 7 to 10 guitars of a specific style. This has to do with their computer system. A shop number batch of guitars will be in the same style, so the tops will all be within the grade designated for that style.

But as with most things Martin, nothing is as simple as all that.

Grade 8 is the highest grade. It is officially reserved for Style 45. An 8 would have very even grain, or at least the grain would be nicely bookmatched between the two halves, with very little in the way of run out, and an even color across the entire top.

But there are many Martins made with Grade 8 tops that are not 45s. For example, the OMC-28B I once owned, the Brazilian rosewood Laurence Juber model, had clear markings that read “8A LE” written on the underside of the top, which I assume stands for “Grade 8 Adirondack, Limited Edition.” I have never seen that exact grading before or since.

Grade 7 is designated for Style 42 and Style 41.

But most 40s Series and special editions getting spruce of the highest grade are actually designated as Grade 7 – 8. I guess that is because different people do the grading based on work shifts and perhaps one man’s 7 could be another man’s borderline 8. I have seen OM-42s and D-42s with tops that appeared flawless to my eye, so why they were not an 8, or if they were 8s that ended up on a 42, I do not know.

When it comes to custom orders, the Custom Shop employees have more time and leeway to think about a specific guitar and what top they think will look best with the overall aesthetic design. But they are still expected to stay within the grades meant for that style, unless the customer has requested and is paying for “premium” woods. But custom Martins seem to end up very good looking tops more often than not.

Grades 6 and 5 are designated for Style 28 on up to and including Style 40.

Although sources inside Martin will say a D-28 and an HD-28V will both be spec’d for a Sitka spruce top of Grade 5 – 6, regardless of the series, my experience showed me that Style 28 guitars in the Vintage series had tops with so much cross grain it looked like woven burlap. However, that effect could have been intensified by the “aging toner” applied to the spruce to make it resemble a top that has aged for decades. There is still plenty of woven fabric looks to other 28s out there.

I have also noted that a higher percentage of Standard D-28s have various anomalies in the grain of the spruce tops, compared to HD-28s or D-35s. And by that I mean patches where the grain swerves, or has the odd bearclaw mark, etc. But even then we are talking about high quality spruce and many people like having some sort of unique figuring that gives their guitar a one-of-a-kind appearance. But this could all be due to a relatively small sampling. Across all D-28s and HD-28s made in the past five years, there may be as many anomalies seen on the one model as the other.

Grade 4 and 3 is designated for Styles 21 and 18.

Before the Second World War, rosewood backs and sides with grain patters that the conservative Martin guitar company deemed too flamboyant or unusual to put it on a Style 28 guitar was used on Style 21. And as the least expensive rosewood style, 21s were given the same grade of top as a mahogany Style 18 guitar, even though a 21 had fancier trim and fret markers. By the mid-1950s, Style 21 was simplified so that the newly released D-21 was basically a D-18 made with rosewood.

In modern times the tops on guitars made in Standard Style 18 or 21 and a those from the Vintage series were officially spec’d for the same top wood, even if the Vs often seemed to have better looking tops, to my eye.

But today the Standard D-18 is the D-18V, only with the V neck replaced by Martin’s new high performance neck. And the top on the one I own looks great and sounds even better. I have yet to see a modern OM-21 alongside the new OM-28 that replaced the OM-28V, so I cannot comment on whether there is an obvious difference in the look of the tops.

Martin does not have a Grade 2 or 1.

Anything like the Road Series you asked about gets Sitka spruce tops that are not given specific grades, but fall outside of the level used for the Standard Series and above. But again, we are still talking about a level of quality above and beyond what most of the industry uses for their guitar tops.

And it is true various people own Martin guitars with visible grading marks under the top that suggest a higher grade than that style was supposed to get. I own one of them, a custom ordered 000 based on the 000-18GE in terms of size, neck and string spacing, but made with Madagascar rosewood, maple binding and the Vintage Style 28 used on the Laurence Juber models.

I did order it in person, at the Martin factory, from the head of the Custom Shop at that time, and I believe it is the first custom Martin made in Madagascar rosewood. But it cost so much I did not fork out for premium grade Adirondack. So it should have been a Grade 3 – 4 top.

Under the Adirondack spruce soundboard is written a “7” along with a very small “000” a little ways off from it.

I guess somebody up there likes me.

And that is one man’s word on…

Martin Wood Grading


15 thoughts on “Martin Wood Grading

  1. This was a fantastic article and addressed several of my concerns. As the owner of a D-18a aged, OM-18a and a Gruhn custom 0000-21, I found several particular areas of interest. Also, I’m thinking about pulling the trigger on a Custom 0000-14F FGL that has an adi top but stated std 3-4 grade. So my concerns, having read this article have now been alleviated. Thank you so much and I look forward to reading more of your interesting and informative articles.

  2. Thanks for this really informative post. Hopefully you’re still checking for questions since it’s been a while. I have two questions:

    1. Do the Alpine spruce tops (italian, swiss, etc.) have the same grading system as sitka and adirondack? I’m not sure if they have enough volume of supply to differentiate at the same granular level as the more common tops. I think that they currently are only available on custom builds and the price generally falls between adirondack and sitka.

    2. Is there any way of viewing the wood before it is assigned to the guitar you’ve commissioned? I’m just about sure the answer is no but wanted to ask anyway. I’ve read that when dealers go for visits they can view some inventory and choose which to bring back to their shops but even those are already built. Back in the 90s I was able to go to Bourgeois and see him tapping tops and selecting mine which was cool. Of course with my level of knowledge he could have been tapping plywood and I wouldn’t have known it!

    Your comment about earlier high end models only getting straight grain backs because irregular patterns were looked down on makes me think there may be some real hidden gems out there in the vintage lower level guitars when it comes to tone. I’m not a big vintage guy but I don’t see many 21’s out there…maybe if they were less expensive they weren’t treated as well over time and fewer survived.

    1. Thank you Dennis, for your queries.

      European spruce is segregated as Premium and Standard grade, or maybe they call the latter Normal grade. It does show up on catalog models now and again, usually Special or Limited Editions.

      Currently, the only way a Custom Shop customer can select the wood for their guitar is through special arrangement with their dealer, who must be present alongside the customer at the factory at the time of the appointment. And it comes with a hefty fee. I assume this service has been suspended due to the current health crisis.

      This is a change from the previous way, where you simply paid the fee and a Custom Shop elf took you to a relatively small stack of wood, and allowed you to see some five or ten sets from which to choose your back and sides, and top as well if I recall.

      But without that special event, the Custom Shop employees still do this on their own, trying to find a set they like for the size of guitar they will be making, and looking for a top they think will go well with that set. That is very different from the guitars made outside the Custom Shop, where they are expected to take whatever is on the top of the stack.

      D-21s and 000-21s do in fact sell for a good deal less than 28s and can have some very nice rosewood. They also have rosewood for the bridge and fretboard, and this does make them sound differently, being a little brighter and less meaty.

  3. I’ve just purchased a OOO-28 Custom with Adirondack top Toasted Burst and noticed on the build sheet that it is a std and grade 3-4. It was my belief that all 28s used a grade 5-6. Did I just buy a sub-par instrument as far as wood grade goes? I purchased sight unseen so I’m hoping for the best on sound quality.

    1. Hi Christopher, and thank you for your query. Style 28 is spec’d for Grade 5-6 Sitka or Grade 3-4 Adirondack, which fall into a similar price range. My custom Martins have tended to be Grade 3-4 Adirondack. From my experience the biggest difference between the 3-4 Adi and the 5-6 is color variation, with the 3-4 having more noticeable streaks of darker hue.

  4. I have a 2014 Custom Shop D28 Marquis with an Amber Top. The spec sheet states Grade 5/6 for the top. The Adirondack looks to me better than that.
    How can I find out??



    1. Hugh, thanks for your question.

      For many years the grade was written in pencil on the inside of the top, back by the end block. Martin changed this recently, because they started putting their graded top sets in batches and the markings for the batch were placed outside the area that is cut to make the shape of the top. I no longer remember when they instituted this change.

      So, you could get an inspection mirror and a light and go looking for any writing on the top, inside the guitar.

      If you contact customer service with your serial number, they will likely tell you Grade 5/6 because that is what Style 28 is spec’d for. There will be no record of someone deciding to pick from a higher grade stack. I am unsure if that is even allowed these days. So, it is likely that grade.

      However, the custom shop employees are allowed to do more than take the one on the top of the stack. They may look at a few and pick one they think will work well with the back and sides wood, or simply because they like the look of the particular top.

      The reason your top was graded as it was is based on the individual who was doing the grading. One man’s 6 is another man’s 7 often enough, or one woman’s for that matter. From my experience custom shop tops usually look better than most tops I see in shops among the Standard Series instruments.

  5. I watched the 6 video series on the martin guitar factory tour. When they were at the grading station they were candling the tops with some kind of black light. they showed how imperfections not visible to the naked eye could be detected under this special back light.

    1. Yes. There are many things that are hard to notice, and others that cannot been seen at all. Some show up only after sanding and finishing. Various toner can bring out features that were not obvious or even visible in the unfinished wood.

      And while the veteran graders know how to spot things most people don’t, even they cannot see every anomaly without such aides.

  6. What wood grade would my new 6/2018 1937 Authentic D28 have for the VTS Adirondack top and EIR?

    1. Technically, your wood is the same grade all Style 28 guitars get. But A) You have Grade 5/6 Adirondack Spruce and Standard Grade Madagascar rosewood, which has only Standard and Premium grade. I consider both to be significant upgrades from the woods used on the typical professional-level Martin. And B) your guitar is made in the Custom Shop, by people who have the OK to actually take some time looking through the stacks and hand-pick the sets, rather than just take the first thing at the top of the pile.

  7. I read somewhere that on standard series, the herringbone (hd28) got 1 grade higher than non herringbone (d28)?

    now I wonder if vintages series (hd28v) get the same grades with standard herringbone series (hd28)?or higher grade?

    1. Martin wood grading is pretty basic.

      There is only two grades of Indian rosewood (for guitars made in Style 21 and above.) And the spruce grades these days are spoken of in the same manner, Premium grade and non-Premium grade.

      Traditionally it has been like this…

      Style 42 and 45 got Premium grade rosewood.

      Style 18 (which is mahogany back and sides) and Style 21 got Grade 3 – 4 spruce tops.

      Styles 28, 35, 36, 40, and 41 got Grade 5 – 6.

      Styles 42 got Grade 7 – 8

      Style 45 got Grade 8

      However, the grading is done by more than one person and rather quickly, using examples on the wall to point out certain things to look for in terms of grain. And back when they wrote the grade number on the spruce, so you could see it with an inspection mirror, it was clear that sometimes a guitar might end up with a higher grade than its style dictated. And there were also other markings.

      For example, the OMC-28B Laurence Juber Brazilian signature model has a top marked 8 A LE, for Grade 8 Adirondack Limited Edition.

      But the people who are getting a top off a stack do stop and look at it and say which one of the two three they have time to check out looks like it will go well with the overall guitar they are working on.

      The people in the Custom Shop have a little more time and leeway when it comes to picking out a particular top.

      And the same basic hierarchy applies to the Adirondack spruce used on the GE/Marquis and Authentic Series instruments. A D-18 Authentic gets a Grade 3 or 4 Adirondack spruce top, just like it did in 1936. The difference of course is what qualified for that grade back then was a bit tighter and better looking than what you see now a days.

      Internally, they still use that system when spec’ing out a model. But the wood graders can vary in what they think qualifies for one grade or another. In other words, one grader’s 5 is another grader’s 6.

      As for the Vintage Series, in the 1990s I was told that the tops on the 18s and 28s were on par with Style 40 tops in the Standard Series. But, technically, the 28 and 40 were the same grade already. So there were some unwritten levels in that large range between Style 28 and 41.

      I do not know if it is true that HD-28s were given better looking wood than the regular D-28. That could just be guitar shop marketing speak. But I think it is safe to say the HD-28V did once upon a time.

      And it is true that HDs sometimes got Engelmann spruce in the 1990s and before, just because some of it happened to be available. But I never heard or saw a Standard D-28 with that spruce.

      The Vintage Series instruments do/did always seem to have really great cross weave, tons of it, which I often liken to looking like burlap or other woven fabric.

      But I have seen tops on recent 18s and all sizes of Standard 28s that have it these days too.

      Martin has recommitted themselves to making the Standard Series the main focus and the improved looks of the 18s and 28s, and of course the makeover of the entire 18 line up is proof of that.

  8. What’s the difference between premium Mohagany and std. Also do the authentic get premium tops. My 00-18a has a very uniform and narrow grain lines with cross silking.

    1. Walt, it sounds like you got an exceptionally fine top even by Authentic Series standards.

      Any difference in wood grading at Martin is based on what it looks like. I do not know how they feel about mahogany, as in do they think banding (noticeable striping) is considered better than no banding where it grain is basically a uniform peppering all over. Given the shortages of mahogany today, there are probably anomalies in some wood panels like scaring or worm holes that need filler which show up on mahogany guitars that would have been rejected in the past. So that may figure into what mahogany ends up on the guitars form what series.

      As for spruce tops, the various styles (18, 28, 45…) get the same grade they would have whenever the vintage Martin being copied would have received. As I recall, that means Style 18 and 21 gets Grade 3-4, Style 28 and 35 get Grade 5-6. And this is the same for all Series.

      Personally, I feel this is a bit wrongheaded for the Authentics. What qualifies for Grade 3-4 today often has much wider or less uniform spacing to the grain than what was typically seen in on a D-18 from the 1930s.

      However, even the lowest grades of spruce tops at Martin are better than what is found on 75% – 90% of the acoustic guitars for sale in the world. So one is still getting a great top, even if the width and spacing of the grain lines are often not as tight or as uniform as they were back in the day.

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