Understanding Martin Model Designation

Since they can seem confusing to those unfamiliar with the arcane hieroglyphs,
here is a primer of C. F. Martin & Co. Model Designation

The Model Name – two sides of a dash

There are two halves to a typical Martin model designation, with the name separated by a dash.

Example: D-28

The first half refers to the “size” or physical dimensions of the guitar, and the second half refers to the visual appearance of the instrument and the materials used to create it, known as the instrument “style.”

REVISED: July 3, 2018

*Note: that statement and what follows does not include the designation “14”, as in D-14, 00-14.

This is a modern invention to denote a 14-fret guitar that a Martin dealer ordered with custom specifications in size D, 00, et al. SEE BELOW*

Size

The body size was originally designated as a number. In staying with customary sizing used by toolmakers and woodworkers, the higher the number on the left side of the dash, the smaller the size of a Martin guitar. Some models introduced in the twentieth century use letters for their size indicator.

C. F. Martin Sr. founded his business in 1833 and was soon offering guitars in sizes ranging from a tiny size 5 on up to a size 1, which still seems amazingly small by modern standards.

So when they needed a larger size, Martin used Size 0. It was considered large enough for a public concert. Hence the term “concert model.”

As guitarists began to perform in larger halls, alongside banjos and the mandolin, C. F. Martin Jr. offered the 00 in 1873, the same year C. F. Sr. passed away. It was deemed an extra-large guitar for a “grand concert,” and that term has been used to describe guitars of this or similar size throughout the guitar world ever since.

The 000 followed shortly after 1910. It was looked upon as enormous at the time.

All of these sizes were originally traditional 12-fret neck designs, typically employing gut strings. Be they 12 or 14-fret guitars, the most common Martins of the twentieth century can be equated thus:

0 = Concert, 00 = Grand Concert, 000 = Auditorium, 0000 = Grand Auditorium (aka size M,)

OM = shares the same body size as a 000, but typically has other differences.

D = Dreadnought (similar to Gibson’s Jumbo size,)

J = Jumbo (similar to Gibson’s Super Jumbo size.)

Arriving after year 2000 were the Grand J = Grand Jumbo (similar to Guild’s Jumbo,) GP = Grand Performance (similar to Taylor’s Size 14 and the “Small Jumbo” size of many other makers,) and 00L = a 14-fret 00 with Long silhouette due to its “slope shoulders” that are similar to a 12-fret Martin. They were inspired by the Gibson size L guitars, but retain the same depth as other Martin 00 and 000 guitars.

Other builders of guitars have adopted terms like OM and Grand Concert for generic use since the 1970s, typically indicating a 14-fret instrument with a smaller size and narrower waist than the Dreadnought or Jumbo body shapes.

As stated above, “grand concert” originated with Martin’s 12-fret body size of the 1870s. But in its original definition, OM for Orchestra Model actually meant any 14-fret steel string Martin, as opposed to their 12-fret guitars originally designed for gut strings. Initially, the original 14-fret Martins, invented in 1929, were made in the Auditorium size only and given model stamps like OM-18, OM-28. The stamp and model names were changed back to 000 in 1934, when Martin converted all their sizes to 14-fret orchestra models. See below for the differences between modern Martin OMs and 14-fret 000s.

Here are the dimensions of common Martin body sizes available today.

14 Fret – 6 String

Size 0 00 00 Deep Body 00 Sloped (L00) 000/OM
Total Length 38 3/8” 38 5/8″ 38 5/8″ 39 9/16″ 39 13/16″*
Body Length 18 3/8″ 18 7/8″ 18 7/8″ 19 7/16″ 19 3/8″
Body Width 13 1/2″ 14 5/16″ 14 5/16″ 14 3/4″ 15″
Body Depth 4 1/4″ 4 1/8″ 4 5/8″ 4 1/8″ 4 1/8″
Grand Performance 0000 (M) Dreadnought Jumbo Grand Jumbo
Total Length 40 3/8″ 40 5/8″ 40 1/2″ 40 5/8″ 41 1/2″
Body Length 19 3/4″ 20 1/8″ 20″ 20 1/8″ 21″
Body Width 15 3/4″ 16″ 15 5/8″ 16″ 17″
Body Depth 4 1/2″ 4 1/8″ 4 7/8″ 4 7/8″ 4 7/8″

* Short-scale 000s have slightly shorter Total Length than OM due to shorter neck.

12 Fret vs 14 Fret – 6 String

12 Fret 00 000 Dreadnought
Total Length 37 3/4″ 39 5/8″ 37 7/8″
Body Length 19 5/8″ 20 9/16″ 21″
Body Width 14 1/8″ 15″ 15 5/8″
Body Depth 4 1/16″ 4 1/8″ 4 7/8″
14 Fret
Total Length 38 5/8″ 39 13/16″ 40 1/2″
Body Length 18 7/8″ 19 3/8″ 20″
Body Width 14 5/16″ 15″ 15 5/8″
Body Depth 4 1/8″ 4 1/8″ 4 7/8″

 Style

The instrument Style is also represented by a number. With few exceptions, the higher the style number on a Martin model, the fancier and more expensive are its materials and appointments.

Typical examples of model names include: 000-18, D-28, OM-45.

A 000-18 stands for Size “Triple Oh” (or at the Martin factory, “Triple Naught”) in Style 18, which includes mahogany back and sides, and a top of spruce, with dark bindings on the body, an unbound neck and white dots on the fingerboard, etc.

A D-28 stands for a Dreadnought body in Style 28, which includes rosewood for the back sides, a spruce top, white binding and typically ebony for the fret board and bridge, etc.

An OM-45 is an Orchestra Model size in Style 45, the top of the line for a basic catalog model, which includes top grade rosewood with abalone shell inlaid along the edge of the spruce top, as well as every edge along the back and sides, in addition to fancy, abalone fret markers, and decorative binding on the neck, etc.

In modern times, additional indicators have been added onto some model names.

i.e. 000-18GE 1937, HD-28VS, JC-12-15E. These translate to:

000-18GE 1937000 size in Style 18, with specs designated for the Golden Era Series of vintage reissues, in this case based upon the 000-18 made in 1937.

HD-28VSHerringbone-trimmed Dreadnought size, in Style 28 with specs of the Vintage Series, using the 12-fret version originally known as the Standard body design. Guitars with the designation H for Herringbone in their name came with scalloped braces, at a time when many Standard Series Martins did not have scalloped braces. Examples include HD-28, HD-35, and the no-longer-made 000-28H. Today, Standard Series 28 models with the H also get the 1930’s style Zig Zag back strip, while those without the H get the later Style 28 back strip.

JC-12-15E*- Jumbo size with a Cutaway body, 12 string guitar in Style 15 with a built-in Electronic amplification system. The designations of 12, C, and E stand for 12 String, Cutaway and Electronics throughout the Martin line, e.g. MC-28, D-18E, HD-28-12.

* Martin never actually made a JC-12-15E. A pity really. I would have bought one if they had.

Designation 14:  As mentioned above, “14” when appearing in shops or on line as in D-14, 000-14, etc. means it is a 14 fret guitar ordered from the Martin Custom Shop. It is used the way “Orchestra Model” was once used to mean the 14-fret neck design vs. the Standard 12-fret design.

14 does NOT denote the guitars “style.” Quite the opposite, since it does not give any indication of what wood or non-wood materials were used to build the instrument, what sort of neck joint, neck block, bracing, finish, the instrument has, as would an actual Martin style designation like 18, 28, 45, etc.

It is not unheard of for some merchants to order customized Martin guitars based on various lower-level Series not represented in this article, which are dressed up to appear like higher-end models, and then price them beyond their merits when it comes to what is under the hood, as it were.

When shopping for Martin guitars and you see something listed as a D-14, or OM-14, ask the dealer what was the base model or “starter model” for the custom guitar in question, which will tell you a lot more about the level of quality and construction than may be obviously apparent. If they do not know, they can look it up.

TABLE: Common Styles and How They Vary Based on the Series

Notes: In 2018 Martin released a revised version of their Standard Series specifications, which homogenized certain features, like the shaping of the neck, and the use of forward-shifted bracing on all Standard Series models above Size 000/OM. These models currently have the suffix (2018,) except for the Standard D-28, which has (2017.) I will differentiate the current styles with the same suffixes in the table below.

2018 models with E in the model name come with either Fishman Aura VT Enhance electronics or LR Baggs Anthem electronics, depending on the preference of the specific Martin dealer.

All Standard Series six-string Martins now have the High Performance Neck. This is defined as a Modified Low Oval Profile to the neck shape, and a fretboard with the High Performance Taper, which starts at 1-3/4″ width at the nut and is 2-1/8″ wide at the 12th fret, with 2-5/32″ string spacing. It combines the nut width of Martin’s traditional 1-3/4” necks with the 12th fret width of their traditional 1-11/16” neck, and with string spacing a smidgen wider than that on the old 1-11/16” neck models.

Standard Series 12-string models have a modified version of the High Performance Neck.

Previous Standard Series models had a 1-11/16” Low Profile Neck with 2-1/8” string spacing, except OMs, which had a 1-3/4” Low Profile Neck with 2-1/4” string spacing, and the 000-42, which had a short-scale 1-3/4” Modified V neck, similar to the Eric Clapton models.

All Standard Series Martins have Antique White binding as of 2018, except Style 18 and Style 21, which have faux tortoise binding.

As of 2018, all 0, 00, 000 models in the Standard Series have the 24.9” short-scale neck, while OM, GP, GPC, M (0000), D, J, GJ models have the 25.4” long-scale neck.

All styles have 100% solid tone woods throughout. Style 18 has mahogany back and sides, all others listed below have rosewood back and sides.

Style Standard Series Vintage Series GE/Marquis Series
18 Style 18 was revised in 2016 and currently has genuine Big Leaf Mahogany back and sides, Sitka spruce soundboard and bracing, ebony fingerboard and bridge, mother of pearl fingerboard dot markers, open-backed tuners, tortoise colored binding and pickguard, aging top toner, with an overall appearance reminiscent of Style 18 from the late 1930s.

Forward-shifted, scalloped 5/16” braces on D-18, D-18E (intro. 7/17,) DC-18E, GPC-18E, GP-18E (intro. 7/17.)

Scalloped 1/4″ braces 0-18, 00-18, 000-18, OMC-18E, OM-18E (intro. 7/17.)

Previous Style 18:

Rosewood was used for the fingerboard and bridge from 1940s until the recent return to ebony. Pickguard and binding was black plastic between 1966 until the same makeover, when it returned to tortoise.

Non-scalloped bracing on D-18 and 000-18, each having a 1-11/16″ neck from 1939 to recent makeover.

The D-18V, OM-18V, 00-18V are now retired, but still common on the used market. They have a Modified V neck profile (the D has a 1-11/16″ width at nut and 2-1/8″ string spacing, the OM has 1-3/4″ width at nut and 2-3/8″ string spacing, the 00 has a short-scale 1-3/4” neck with 2-5/16” string spacing.)

The modern Standard Style 18 has many structural and cosmetic features of the Vintage Series instruments, but with the modern High Performance neck rather than a Modified V neck.

Example: D-18 Golden Era

Add Adirondack spruce top, 1-3/4” Modified V neck with ’30s Style heel (tubbier overall feel than standard heel,) upgraded tuners, wood fiber inlays instead of plastic, etc.

Golden Era scalloped bracing has more wood removed compared to Standard/Vintage Series scalloped bracing, leading to more flexibility and greater resonance under a lighter attack.

18GE had Brazilian rosewood accents, the later 18 Marquis had Madagascar rosewood accents.

 

21 Style 21

Limited to OM-21 model, and D-21 Special (2017.)

Indian rosewood back and sides, Sitka spruce top.

OM-21 has ebony fingerboard and bridge, faux tortoise binding and pickguard.

The D-21 Special (2017) has Indian rosewood fretboard and bridge, and black binding and pickguard similar to the late 1960s D-21. Only 300 produced.

Both models have white dot fret markers, and Style 18 back strip.

Previous OM-21 1990s – 2012: Indian rosewood bridge and fingerboard with white microdot fret markers, tortoise binding and pick guard. No top purfling or back strip.

Old Style 21 was discontinued in 1969. Typically it had Brazilian rosewood back and sides that were too wild or unusual in figuring to use on the stately Style 28 instruments. At the start of the 14-fret era it had a herringbone rosette and back strip, which were discontinued in the 1940s, when Style 21 became, basically, Style 18 with rosewood for the back and sides instead of mahogany, it traded its ebony fretboard and bridge for rosewood at that time as well. The tortoise bindings and pickguard were switched to black in 1966.

N/A 00-21GE was a special edition that had features closer to the Vintage Series (Sitka spruce and Indian rosewood, etc.) than the official Gold Era Series models.
21 Special Limited to OM-21 Special and D-21 Special (pre-2017.)

Add many cosmetic features of Style 21 circa 1940, but otherwise a Standard Series OM and Dreadnought model, but made with rosewood bindings, and Spanish cedar necks that lighten up the weight of the guitar and contributes to a more open, airy sound.

Also, they have a 1-3/4″ low profile neck and 2-5/16 string spacing.

(Both models now discontinued but frequently on the used market.)

N/A N/A
28 (2018) Indian Rosewood back and sides, Sitka spruce top with vintage toner. Ebony fingerboard and bridge.

Antique White binding, herringbone top trim, abalone Diamonds and Squares fret position markers, open back tuners.

Forward-shifted, scalloped braces on all 28 (2018) models.

D-28 (2017) gets large white mother-of-pearl dot markers, forward-shifted, non-scalloped braces.

Previous D-28, along with D-28S (discontinued,) previous GPC-28E, GP-28E (intro. 7/17) have 5/16″ non-scalloped. non-forward-shifted braces.

As of 2018 models with H in the model name, e.g. HD-28 (2018) have the 1930’s style Zig Zag back strip from the Vintage/GE/Marquis Series. Style 28 models that do not have H in the model name get the later Style 28 back strip.

Higher grade Sitka spruce, Diamonds and Squares fret position markers, grained ivoroid binding, Zig Zag back strip, tortoise pick guard, top herringbone trim, forward-shifted scalloped braces. Modified V neck, with 2-5/16″ string spacing, etc.

 

Standard Series (2018) adopted many of these features, but not the grained binding or V neck shape.

Add Adirondack spruce top, 1-3/4” V neck with ’30s heel (tubbier feel overall,) wood fiber inlays instead of plastic, forward-shifted, Golden Era bracing (see Style 18 above.)

 

35 (2018) Indian rosewood sides and three-piece back. Sitka spruce top with aging in toner, and forward-shifted, non-scalloped 1/4” braces, ebony fingerboard and bridge, white mother-of-pearl dot markers, Antique White binding including neck, faux tortoise pick guard, closed silver tuners with large buttons.

OM-35E and HD-35 have scalloped 1/4” braces.

Pre-2018 Style 35 has stark white binding, black pickguard, natural top toner, non-forward-shifted braces.

OM-35 has scalloped braces. HD-35 has herringbone top trim and back strips, scalloped braces, faux tortoise pick guard.

Style 35 first appeared in 1965 and had Brazilian rosewood (until 1969,) and faux tortoise binding and pickguard, which were changed to black in 1966.

“35” has appeared in the model name of several special or limited editions, with woods or appointments different from above. The defining 35 features being a three-piece back and a bound fingerboard.

Example: HD-35 CFM IV 60th Anniversary and D-12-35 50th Anniversary.

N/A N/A
40 (2018) Currently limited to J-40

Same wood grades as Style 35. Indian rosewood and Sitka spruce, forward-shifted, scalloped bracing, 7-ply black and white strip top trim, abalone rosette and small abalone hex fret position markers, bound High Performance neck, Abalone headstock inlay and gold color open back tuners, Style 45 mosaic back strip.

Pre-2018 Style 40 had white binding, 1-11/16” Low Profile neck, non-forward-shifted scalloped braces, black pickguard depending upon year of production. D-40 was basically an HD-28 with fancier pearl appointments and a bound neck. J-40 was also available in all-black finish.

Pre-war Style 40 had short snow flake pattern fret markers and abalone top trim like pre-war Style 42, but no pearl around fretboard extension.

 

N/A N/A
41 (2018) Currently limited to D-41 (2018.)

Higher grade Indian Rosewood and Sitka spruce than 28 or 35. Abalone shell trim around top and rosette, but not the fingerboard extension on the soundboard. Abalone hex inlays on neck. Forward-shifted scalloped braces. Aging top toner, Antique White binding, open-gear tuners.

Pre-2018 D-41 had non-forward-shifted braces, natural top toner, white binding. Earlier examples have black pickguards rather than faux tortoise.

D-41 from first year of production (1969) have Brazilian rosewood back and sides. Non-scalloped bracing before 1986.

Style 41 Special – Vintage Style 45 snowflake fingerboard, grained ivoroid binding, forward-shifted scalloped braces (Size D and Size J) and Modified V neck (1-3/4″ neck width on OM-41 Special.)

N/A N/A
42 (2018) Highest grade Indian Rosewood and Sitka spruce with aging top toner. Abalone rosette and top trim including fingerboard extension. Fretboard has Vintage Style 45 snowflake inlays on fingerboard and bridge, Antique White binding, faux tortoise pickguard, gold-color open gear tuners.

D-42 has forward-shifted bracing, OM-42 has 1/4” bracing.

Pre-2018 Style 42 has grained ivoroid binding, Low Profile neck, 1-11/16” for D, 1-3/4” for OM. 000-42 has 1-3/4” Modified V neck.

N/A Limited to 000-42 Marquis (discontinued.) Add highest grade Adirondack spruce top, 1-3/4” Modified V neck with ’30s heel, wood fiber purfling around the pearl trim instead of plastic, etc. Short snowflake pattern on fingerboard. 1/4” GE, scalloped braces.

Vintage Style 42 can be seen on the 2016 000-42 Authentic 1939 with usual Authentic specs (hide glue construction, VTS torrefied Adirondack top, etc.)

45 (2018) Currently limited to D-45.

Highest grade Indian rosewood and Sitka spruce. Abalone trim on all edges of top, sides and back, hex inlays on neck, etc. Abalone hex fret markers. Forward-shifted, scalloped braces, Antique White binding, gold color open gear tuners, faux tortoise pick guard.

Pre-2018 Style 45 has white binding, natural top toner, non-forward-shifted braces, 1-11/16” Low Profile neck.

Earliest modern examples (1968-69) had Brazilian rosewood and European Alpine spruce tops, changed to Sitka shortly thereafter, Indian rosewood from 1970.

Black pickguard replaced with tortoise in recent years.

Add Modified V neck, pre-1938 Style 45 snowflake fingerboard pattern, grained ivoroid bindings, vintage top toner, tortoise pick guard, forward-shifted scalloped braces.

Style 45 (2018) adopted much of this styling, except fret markers, binding, and neck shape and size.

Same as Vintage Series, but add highest grade Adirondack spruce top, 1-3/4” Modified V neck with ’30s style heel, wood fiber purfling around the pearl trim instead of plastic, Golden Era scalloped bracing (see Style 18 GE above.)

Note: specs listed are only notable examples.

* Authentic Series not included in this table. Each Authentic model is an as-close-as-possible recreation of a specific Martin guitar from a specific year. Examples include D-18 Authentic 1939, OM-28 Authentic 1931, 00-18 Authentic 1931. See specific reviews HERE.

** The Golden Era Series was introduced after the Vintage Series, to offer more-accurate vintage reissues, which included the use of Adirondack spruce and also Brazilian rosewood as back and sides on Styles 28GE and 45GE and for cosmetic trim on Style 18GE guitars. Prior to the official series getting under way, a version of the D-18GE was made with a Sitka spruce top, as was a 12-fret 000-28GE.

The Marquis Series was introduced after the shortages of Brazilian rosewood halted GE production. Marquis guitars are basically identical to GE models, except for the substitution of Brazilian rosewood with Indian rosewood on 28 Marquis and 45 Marquis, as well as Madagascar rosewood as trim on 18 Marquis. Some additional, minor changes occurred over time, like the brand of tuning machines, etc.

Surviving members of the Vintage Series, Golden Era Series, Marquis Series, are currently found with the Authentic Series under the umbrella of Martin’s “Vintage and Authentic Series.”

Just the Facts

Q: Why are there many numbers missing among the Martin Style names?

A: Some styles have gone extinct. The earliest Martins were made in a variety of sizes and cosmetic trim. At one point, Mr. Martin matched one body size with one style of trim. Each was assigned a specific price. A guitar in Size 1 cost $17 and became known as Style 17.

Once prices began to rise, the original Style names stuck, but were associated with the specific trim rather than the price. These set trim styles eventually began to appear on different sizes. Old C. F. died in 1873 but his son and grandsons continued to use and expand upon his methods. By 1900 the current system of Size on one side of the dash and Style on the other was well in place.

Some Style numbers that were gone by 1950 have been resurrected, but with cosmetic specs or woods that are different from their original version.

Example: Style 17

Style 17 had Brazilian rosewood back and sides and a spruce top in the 1800s. It was changed to mahogany back and sides circa 1906 and was retired in 1918, when Style 18 was switched from rosewood to mahogany.

Style 17 was reborn in 1922, in all mahogany (including the top,) with a satin finish (similar to today’s Style 15, which only existed as the 0-15 with a spruce top until 1940, when it was given a mahogany top.)

Style 17 was made in smaller and smaller numbers until retired in 1961 (with a one year resurrection in 1967.)

It returned again as a fancier version of modern Style 15, with white purfling and a high-gloss finish, before being put to bed yet again.

More recently, Style 17 was revived as basically a 15 Series guitar with a spruce top instead of mahogany, and with a reddish finish tint and sunburst top in a 14-fret Dreadnought size and a 12-fret 000, the 000-17S. Those have since been retired.

In 2016 three new sizes were offered in Style 17 (the 12-fret 00, 14-fret 00L, and 14-fret 000), with two new cosmetic packages, the Black Smoke (all black with white trim and pickguard) and Whisky Sunset (bronze-orange to black sunburst.) And Style 17 is now re-positioned as Depression Era budget guitars made of all solid wood for players looking for a great value with a spruce top.

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More details about Martin model designations

When compared to current designs, Martins prior to 1930 were similar to modern, Classical guitars in many respects, all having an elongated shape with a wide 1-7/8″ neck that offered only 12 frets clear from the body and top braces intended for gut strings. In fact, Martins were the preferred choice for American concert professionals performing the classical repertoire in the decades between the Civil War and the Second World War.

Martins moved into a position of prominence in popular, country, and folk music once their 14-fret steel string guitars appeared during the Great Depression. Andre Segovia’s tours of the US during the 1930s and ’40s shifted Classical guitar firmly toward guitars that evolved in Spain at the same time Martins were evolving in America.

Martin shifted their own focus toward steel strings during the early twentieth century, but other than their Hawaiian-style guitars meant for playing with a steel slide, they did not design guitars specifically for steel strings until the OM, which first appeared in the 1930 catalog.

OM

The Orchestra Model was the first Martin guitar to break with the numbered size convention, when its model stamp on the neck block was represented by the initials OM. The new design featured a 14-fret neck and a body braced exclusively for steel strings. The new name was meant to attract members of dance orchestra rhythm sections, who were switching from the banjo now that steel strings were becoming the norm for acoustic guitars.

Although some Jazz musicians played the new steel string Martins, it was actually pop music icons singing in front of bands on the new sensation of radio, like Gene Autry and Roy Rodgers, who embraced the revolutionary guitar design. In later years it was traditional Blues soloists, and eventually New Age fingerstyle guitarists who took the OM into ever expanding genre of guitar music.

Because the OM and the 14-fret 000 share the same body size, there is often confusion about how their modern examples differ and why. (See below for more information about that.)

D – Dreadnought

Other model names without numbers include D for Dreadnought. These are the large, now iconic guitar shapes that Martin invented in a 12-fret size in 1916, exclusively for the Ditson musical department store chain, which intended them to be used as the “bass guitar” in mandolin orchestras.

Dwarfing all other sizes at the time, Dreadnoughts were named after the British battleship H.M.S. Dreadnaught (sic), but also as an insider joke. Their largest sizes were the Naught, Double Naught, and Triple Naught. This new size was the biggest Naught of them all.

Martin first offered a dreadnought sold under their own brand name in 1931, and three years later, a 14-fret version was released as well, which became the most popular steel-string guitar design in history. For example, the memorable acoustic guitars played by Johnny Cash, Neil Young, Nirvana’s Kurt Cobain, and Coldplay’s Chris Martin are Martin dreadnoughts.

M or 0000 – Grand AuditoriuM

The M size was introduced in the 1970s. It stood for Grand Auditorium and at times is referred to as the 0000, or Quadruple Oh/Naught. It is a flattop guitar that uses a body shape taken from the mold of a Martin archtop model made during the Jazz Age. They actually used the molds from the 1930s to make the sides.

At its introduction, the M had the widest Martin top, matched with sides having the depth of an OM. Ms are known for their even balance, sounding similar to the Dreadnought but with the bass pulled back in line with the other registers.

J – Jumbo

The Martin Jumbo was the brainchild of C. F. Martin IV, the current CEO. It combines the depth of a dreadnought with the shape and top width of an M. To my ear it sounds like a super-sized 000, with balance across the registers, but with considerable volume, and a focused, punchy midrange.

GJ – Grand Jumbo

Like the M, the Grand J takes its body from an archtop, only this time it was Martin’s modern Jazz guitar, the CF-1. But after some prototype examples, they altered the exact shape a bit. It has a 17” wide lower bout, the widest flat top Martin has ever made. The Grand Jumbo has only been around a few years. It has appeared as normal 6-string and 12-string models. But it has also been used on limited edition baritone models, designed with a longer neck for lower tunings.

GP – Grand Performance

The company’s first totally new flat top body size in many decades. With a top slightly wider and rounder than an OM and a deeper body, they are Martin’s version of the “small jumbo” models that have grown in popularity in recent years. While Gibson’s J-185 from the 1950s might be considered the first true small jumbo, it was in the 1980s that indie luthier Kevin Ryan created the design associated with the term today. But it was a similar design by James Olson that proved most responsible for small jumbo’s surge in popularity among professional artists – mainly thanks to James Taylor adopting Olson’s guitars as his primary concert instruments.

But Taylor’s Size 14 design is what got small jumbos into the hands of the common guitar player, and in 2017 the small jumbo design outsold dreadnoughts for the first time. And Martin’s GP with a cutaway is almost identical to the Taylor design in terms of dimensions, even if they do not sound much like a Size 14 Taylor. In general, GPs sound like an OM with a more pronounced bottom end, and with greater volume.

00L – Slope Shoulder Grand Concert

The 00L (L for Long) size debuted in 2014 with the CEO-7, which was designed by C. F. Martin IV as a nod to Gibson’s fabled L00 guitars of the 1930s. After a couple of limited edition CEO models that combined Martin’s original slope shoulder dreadnought shape with a 14-fret neck, he decided to put the elongated slope shoulder shape on a short-scale 14-fret 00, creating a smallish guitar with a slightly larger sound chamber than the normal 00, increasing bass response. It was a sensational success. The more affordable 00L-17 followed in 2016.

Now back to the OM – 000 confusion…

To make the revolutionary OM, Martin turned to their Standard 12-fret 000, which was the largest size they offered in 1929. Basically, they squashed the slope shoulders down almost flat, which exposed two more frets and pushed the upper bout farther out. This also had the effect of placing the bridge closer to the neck, relative to the overall body length.

Then they narrowed the neck from 1-7/8″ to 1-3/4″ for the target audience of banjoists and added bracing designed to work best with the tensions of steel strings … and viola! They invented the modern, flat top acoustic guitar.

After three years, it was clear Martin was going to convert the bulk of their catalog to the new 14-fret steel string design, so the OM stamp was replaced with 000, sometime in the early months of 1934. This allowed them to get back to their traditional numbered sizes. The 12-fret versions were retired, with a few exceptions, like the 00-21. And some dealers did order the occasional 12-fret Martin otherwise. But the future clearly belonged to the 14-fret Orchestra Models.

At Martin, at least, any guitar made from that point on with the 14-fret design was an “Orchestra Model.” In fact, during the first years that the 14-fret dreadnought was offered in the Martin catalog, it was listed as “Orchestra Model, Size-D”.

Guitars that retained the elongated body and 12-fret neck were referred to as Standard models, and in modern times an S is added to their neck block stamp for “Standard.” This is sometimes confused with guitars made up through the 1950s that had an S added for “Special,” typically meaning some sort of customized Martin guitar from before they had an official custom order policy.

The 14-fret 000s made in the first months of 1934 are identical to the OMs made in 1933. But soon after, changes were instigated in the design. It is my belief that this was due to the tension from steel strings on a relatively narrow, long-scale neck causing too many repair issues. The first major change was having the string scale shortened by half an inch, equal to that on 14-fret 0s and 00s.

The new, short-scale 000s also have their tone bar braces increased from 1/4″ to 5/16″. It remains a question of history as to exactly which came first, the change to 5/16″ tone bars, or the short-scale neck, or if they arrived at the same time.

All 14-fret Martins went to a narrower 1-11/16″ neck in 1939 and the company stopped using scalloped bracing in 1944 (Actually this was transitional, as 1945 Martins have what is now called tapered bracing.)

So, by the mid ‘40s the 14-fret 000 had an auditorium body size and a short-scale neck like the 0 and 00 sizes, but with bracing of the size and density found on the larger dreadnoughts.

The Martin 000s of the 1950s and 60s continued this overall design, as they stood up well to the thick flat picks and steel fingerpicks popular at that time. And they fit well in group playing, as the guitars’ punchy notes could cut through an ensemble without upstaging other instruments.

The Modern OMs

Starting in 1969 Martin answered the call for guitars made in the tradition of the original OM-stamped guitars, with sporadic special editions. The “OM” became an official model type in 1990, which has the same shape as the 14-fret 000. But otherwise, several differences separate the two designs.

The traditional 14-fret 000 had evolved to have a narrow, short-scale neck and 5/16” non-scalloped bracing.

Modern OMs have a wider, long-scale neck and 1/4” scalloped bracing to help simulate the lighter overall build of pre-war Martins. (The OMs made in the 1930s actually had a center X-brace that was 5/16,” surrounded by 1/4” tone bars.)

The lines dividing the 000s and OMs have since blurred, due to all the vintage reissue models and limited editions that have come out in the past 25 years.

Traditional 000 necks have the short scale, while 000s below Style 18 have a long-scale neck, since that is now the industry standard. But the new 2016 000-17 has returned to the short scale neck and also acquired the modern High Performance neck. Martins shall ever and always continue to evolve.

Vintage-style 000s often have a 1-3/4” neck, like the Eric Clapton models and the pre-2018 000-42. But they are different than the 1-3/4″ High Performance neck, which is narrower in the upper frets and has a much lower profile.

The modern 000-18 and the 000s from the Marquis/GE series also have 1/4″ OM-style bracing to help make them sound like the lighter, more resonant 000s from the 1930s. This is partly because modern guitars are made with thicker wood and finishes to withstand the rigors required of a lifetime warranty.

Some Limited Edition/Custom Artist OMs, like the John Mayer and Paul Simon models have necks narrower than 1-3/4” and so on.

To confuse matters more, as of 2018 most all OMs and 000s have been converted to the modern High Performance neck. It has a 1-3/4″ width at nut, but the overall neck is closer in width and string spacing to a traditional 1-11/16″ Martin neck. It is just cheated a bit wider down in the “cowboy chords” area below the 5th fret.

Despite the many exceptions, it is safe to say that typical Martin OMs have lighter, scalloped bracing matched with a long-scale neck that has a 1-3/4” width at nut. Any other defining characteristics depend greatly on the specific year or era of construction.

OMs are recognized today by their small, roundish pick guard, often called a “tear drop,” even though the original OMs from the 1930s switched to the longer Martin pick guard about six months into production.

How do they sound? To my ear a typical 000, with 5/16” bracing, has a focused, punchy voice that cuts well as a lead guitar but on the whole is a more intimate instrument.

The OM has different dynamics leading to a different kind of voice. With its lightly braced top matched with the string tension of a long-scale neck, the OM has a more open voice with greater fundamental note separation, a wavering resonance and greater projection, sounding clearer farther away than a 000, which can sound just as loud as an OM to the guitarist, but drops off over distance. Overall, it has a lot more going on behind and around the top voice (fundamental string notes and high harmonics,) while the 000 puts most of the energy and sound into that fundamental top voice while the undertone plays more of a supporting role.

But compared to other sizes and types, Martin OM and 000 remain closely related in look, feel and tone. They are famous for having a more-perfect balance to the volume of each string, compared to all other 14-fret guitars.

This quality is also the hallmark of the 12-fret 00 and the 12-fret D sizes, even though the dynamics and volume vary greatly between the three designs.

Read More at: Martin’s 000 vs. OM, What’s the Diff?

And that is one man’s word on…

Martin Model Designation

Note: This illustration dates from the late 1980s most likely. The MC is shown with the deeper cutaway that was used on the original design, which had an oval soundhole. The Jumbo size is not listed but it has the same silhouette as the M. Sizes SJ, GP, and 00L were introduced in the twenty-first century.

More About…

C. F. Martin & Company

Martin Authentic Series

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35 Comments

35 thoughts on “Understanding Martin Model Designation

  1. I never post anything. But I have to say, this is the clearest, most concise explanation of Martin & Co’s History and that of their guitars anywhere on the internet. I’m very glad I came across this as I’m reasearching the next guitar to add to the collection.

  2. I am posting here because someone named Kevin tried to post here a while ago with questions about an unusual custom Martin design. I tried to reach out to him via the email address he listed, but it comes back undeliverable. So Kevin G., if you are out there, drop me a line at oneman@onemanz.com

  3. You are awesome for doing this! Any update on the GPC vs. OMC designations – they seem like the same guitar?

    • I am working on the revision of this page right this very minute, in fact.

      Technical difficulties have kept me from putting up much content so far this year, but that is being resolved. Thanks for the comment!

      A quick answer is, the GP design has a wider top and a deeper body than an OM. But the specific specs will be appearing soon.

  4. Hi, so I was kind of confused what the the difference between higher grade rosewood(41) vs highest grade rosewood(42 & 45) assuming same model and body size? Does it really impact the tone or just more like for cosmetic purpose. Thanks for your post. It help better what those number means.

    • Martin grades its wood entirely on looks. The primary reason straight grain has a better reputation, and quartersawn wood most of all has to do with stability of the very thin plates of wood being used, over the long haul. But many people have guitars made with “slab cut” wood that never develop any cracks etc.

      Now, there are those who feel certain visual clues can denote good tone, but it is certainly not reliable. I was having lunch with Tim Teel of Martin Guitars recently when the topic came up and he said there are often times when such indicators do not pan out, when it comes to wood the thinks will be great or a dud and the opposite proves to be the case.

      From my own experience, I did encounter a group of Martin guitars made with Brazilian rosewood, for Mandolin Brothers many years ago. And while I loved the look of the ones with wild grain on the backs, the best sounding guitars were consistently the ones with the most boring straight grain. But that is a very small sample size and could be entirely coincidental.

      It is very interesting now that the D-41, D-42, and D-45 all have the same woods and exact same bracing. The D-45 of course has a trench carved into the sides and back to lay in the abalone, so one could argue those plates will be more flexible than the other two guitars. But otherwise, they three models are more similar than ever before.

  5. Can you shed some light on the classical guitars – the “C,” “G,” and “N” model numbers? Do these letters always indicate a classical, nylon or gut string guitar? Are there other model designations that indicate non-steel string instruments?

    • Hi Gregg.

      Yes all three designate a non-steel string guitar.

      Only the N models were shaped to resemble a Ramirez-style classical guitar. The G models had the same body shape as a 14-fret Martin, but with a 12-fret neck (a concept later copied for the Norman Blake models, which matched a 14-fret 000 body to a 12-fret neck.)

      Only the earliest G models had X bracing. Most have fan bracing.

      The C stood for Classical, but it was the same body shape as the steel-string 12-fret 00. They were very popular in the late 50s on up to the Woodstock era, but as a folksingers guitar more than for the Classical repertoire, although I am sure some people used them that way as well.

      The N models of the late 1980s overlapped with the C models for a time. Other than Willie Nelson’s guitar, they were never big sellers.

      Modern era nylon models have come out there and there, like the 000CDG Doug Greth model and the current the 000C Nylon Cutaway model int he 16 Series that was based on the Greth. They have a cutaway and on-board electronics.

  6. I have a Martin guitar that was purchased in 1964. It was called a folk guitar and the model designation is 00-18C with a the serial number 204752. I can’t find any info on this model from Martin Co. Did they stop making them? If so, what has replaced it?

    • Your 00-18C was in fact constructed at the Martin factory in 1964, so it was brand new indeed. The C in the name stands for Classical. But it does not have the same body size and shape of a Spanish-style Classical guitar. Rather, it has the exact same body shape as the 12-fret 00-21 from that era, but it is has a fan pattern bracing to work with Classical guitar style strings made from gut or nylon.

      Otherwise it has the same specs as other Style 18 instruments from 1963, with mahogany back and sides, Sitka spruce soundboard, Brazilian rosewood fingerboard and bridge, Style 18 binding, trim, rosette, fret markers, and so forth.

      These guitars were very popular, if not made in quite the same numbers as the steel string, 14-fret Martins. Martin introduced the 00-18C in 1962, They made 325 in 1964. The peak year of production was 1967, when 625 were produced. By the early 1970s, production dropped to below 20 made per year. In 1977 5 were made, and then 2 to 5 were made very other year or so into the 1990s.

      Martin’s only attempt to make a Ramerez-style Classical guitar are the N (for nylon) models that came out in 1986. While not exactly the same shape, they have a wider soundboard and less of a waist than the G or C models, with a mosaic rosette more Spanish in style than typical for a Martin. The shot-scale and long-scale N-20 never sold well, the Cs out performed them by a good ways.

      According to Dick Boak, if it weren’t for Willie Nelson’s N-20 “Trigger,” no one would even remember the Ns. But the 00-16C and the 00-18C were very much at the heart of the 60s folk scene.

      A very cool little guitar to be sure.

  7. My dad has a Martin guitar he traded for in the early 1950’s. It’s identification is 0-18 and 114397. What can you tell us about this guitar?

    • Hi and thanks for your query at One Man’s Guitar.

      Your father’s 0-18 was built in 1951. It is made with all solid tonewoods, include Big Leaf mahogany for the back and sides, which may have come from Brazil at that time, but it was found throughout Central and tropical South America.

      The species of spruce used for the sound board is most likely Sitka spruce, from the Pacific Northwest.

      Size 0 was originally made in the 1800s as a 12-fret guitar, and was considered large enough to perform a public concert. The 14-fret version first appeared in 1934.

      Although one did not see many an 0-18 on the concert stage in modern times, they were very popular among the general population during the 1950s’ folk boom.

      Martin made 575 in 1951, compared to 551 of the larger 00-18s and 425 the even larger 000-18s, and 550 Dreadnought size D-18s. And starting in 1952 the numbers for the 0-18 typically exceeded 600 made per year, with a slight drop off here and there until 1970, the last regular year of production, when they made 400.

      Perhaps the most famous 0-18 was the one from the late 1960s that Bob Dylan played at the Carnegie Hall benefit concert for Woody Guthrie, in 1968.

      They only started making them again recently. And after decades of Bigger is Better, the 0 size is making a comeback with younger progressive folk artists.

  8. I have an old Martin Guitar with the numbers 1-17 and 49749 inside the body.
    I wonder what style this guitar is and am confused about how to define it better.
    Thanks for any help you can provide.
    Paul

    • What a cool piece that must be!

      Your guitar is made in Size 1, with Style 17 appointments. With its mahogany top, back, sides, and neck, no bindings and very little cosmetic embellishment, Style 17 was meant to offer an economically affordable Martin. Style 17 at that time is similar to today’s Style 15 (which did not get a mahogany top until 1940.)

      I believe that serial number means your guitar was completed in 1932.

      What is interesting is I think the Martin catalog did not list any Style 17 instruments below Size 2 after the 1920s. Possibly not even in the ’20s.

      But that does not mean dealers were not allowed to order them.

      I would love to see photos. You may want to go to the Vintage section of the Unofficial Martin Guitar forum to see if anyone else knows of a 1-17 from 1932. Yours could possibly be the only one made that year.

    • Hello tonexus. Yes you are correct thus far in your assessment.

      SP – SPecial editions in the 16 Series. They had fancier cosmetic appointments than regular 16s, like the snowflake inlays and abalone trim, gold hardware, and maybe full gloss bodies rather than just the top(?).

      000 – Auditorium size. In that period the 000-16s had a long-scale neck like an OM, but it was a 1-11/16″ neck made with either a Low Profile or a Modified Low Oval, depending on year of production. They also had 5/16″ bracing rather than 1/4″ OM bracing (the original 000C-16 had 1/4″ braces, but 1995 was the last year.)

      16 – The 16 Series originally offered scalloped bracing when Style 18 was still using straight bracing, as well as various cosmetic appointments that were less traditional, or more vintage looking, than the straight-laced 18s. In 1995/6 the 16s were changed to the Mortise and Tenon neck joint and Hybrid A-frame bracing. This resulted in guitars a bit brighter or more brilliant in tone, and with less thickness in the undertone and less wavery resonance, so they have less feedback issues when plugged in and played through large sound systems, compared to the traditional dovetail neck joint Martins.

      C – Cutaway body. These days this is usually placed next to the 000 in the model name.

      R – Rosewood back and sides. The 16 Series are made from the mahogany family, usually.

      E – On-board Electronics. And in those days it was a state of the art preamp with fancier than normal tone controls. Depending on the exact special edition, it would be sliders, or dials, and it might have an on-board microphone to blend into the pickup signal, and a notch filter to screen out feedback friendly frequencies, as is the case with the one you linked to in your comment.

      Congratulations! If yours is anything like the one on reverb, I am sure you will enjoy it immensely.

      • Thank you very much! You have my utmost respect as well. Thank you very much for the very comprehensive answer.

        I suspected R stood for Rosewood. (OK, it was the seller who guessed Rosewood.) It is very much alike the one on Reverb except it looks like that one has no on-board microphone, mine has.

        I truly am enjoying this guitar. I have to, I traded 3 electric guitars plus a bit of cash (and guitar picks) to get this. 😀

  9. Finally!!! the logical explanation that I’ve been searching for. Thank you! The Rosetta Stone is found again!

  10. I have an acoustic/electric single cutaway serial #760407. model #SP00C16AE. date 2001. I can’t find any references. Help?

    • Rick, your SP00C-16AE is a very interesting guitar.

      It is a thin-body acoustic-electric instrument made in the Grand Concert 00 size from solid South American Mahogany and Sitka spruce, with the Fishman Prefix Pro pickup system.

      The point of the thin body is to reduce the chances of feedback when playing at very loud volumes in concert halls and arenas. It has a Mortise and Tenon neck joint and I believe Hybrid X bracing.

      The SP version of Style 16 had the fancier trim of a pearl rosette, a Style 45 back strip, gold tuners, and snowflake and notched diamond-laden fingerboard and bridge made from solid ebony. Given that it was made in 1999, it is probably Macassar ebony from Indonesia, which has natural striping in it.

      This was one of the first models to have the Modified Low Oval neck profile, which has become the rule rather than the exception these days. But it has the standard 1-11/16″ neck in terms of the “taper” to the fingerboard similar to the D-28 and D-45, rather than today’s High Performance Taper – which really is the same neck, only cheated out a bit down in the “cowboy chords” area, so it ends up 1-3/4″ at the nut.

      As it turns out, this model had a Spanish cedar neck, which should help to lighten the overall weight and was probably used to compensate for the rather massive preamp and fancy controls for the pickup system.

    • Hello John, and thanks for your question.

      The W stands for Walnut.

      The back and sides of your guitar are made with American walnut. I do not remember offhand, but I believe it is Black walnut, native to much of the Eastern U.S.

      While it does have the same figuring of Claro walnut from the western U.S., it has very nice tonal properties unique to walnut, which makes it different from mahogany or koa, but being closer to those than the thicker, woofier rosewood tonal spectrum. Personally, I believe it may be a bit more resonant than Claro walnut, but so few guitars are made with either that it is hard to know such things for certain.

    • 🙂

      I know many wives who say so too.

      Martin only makes guitars that sell. So people are buying all those different guitars, and all those different models offered by other guitarmakers.

      As I often said, if we all liked the same thing there would be one model.

  11. As the owner of the following;00028 eric c.om 42,d 35,d 41, d42 and d 45, I cant say how informative this essay is. I can make a little sense out of what I hear(or don’t). Knowing what the differences are helps a lot with the “why” there are differences… if that makes any sense at all. Thanks. Too may guitars

  12. Spoon, thanks for putting this up; so hard to find this information anymore on the CFM website (now in its “second stage” of uh, “improvement”). Keep the flame burning.

  13. I love reading all your stuff. Your enthusiasm is genuine, and your knowledge has my full respect.
    Please continue to write I for one can tell its a labor of love!
    Thank you very much,
    Jerry Eveland

    • Thank you Jerry, for taking the time to say such nice things.

      I call em like I see em, even if not everyone agrees with my own personal strike zone. And that is a good thing. If everyone liked the exact same thing guitars would come in far fewer varieties and most music would sound the same.

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