All About Frets in Acoustic Guitars - Guitar Fretboard

Guitar Fingerboard

Fingerboard of any guitar is the flat section of wood on top of the neck. It is also known as the Fret board for fretted instruments, as the frets are seated into it. Fingerboard extends over to the body of the guitar. This portion is known as “Spatula”or “Fingerboard Extension”.

Guitar Fingerboard Materials:

Overall tone produced by any guitar is the result of complex interaction of various woods forming body, neck and fingerboard of the instrument.  While not as large as the body, fingerboard has sufficient impact on the tone to deserve careful consideration. It also affects the feel of the guitar during play and the aesthetics.

Commonly used woods for fingerboard are:

• Rosewood:  Rosewood is most commonly wood used on guitar fret boards. Rosewood is an oily wood, which absorbs the overtones. So, the resulting tone is rich in fundamental frequencies. Guitars with Rosewood fingerboards is favored by guitarists who want rich and warm tones without pronounced highs. Due to the presence of oil in the wood, Rosewood fingerboards do not require any separate finish. 
• Other hardwoods such as Walnut and laminates are used on inexpensive guitars. 
• Ebony:  This is normally the first choice because of its hardness, feel and crisp attack. Ebony fret boards are preferred by players wanting bright and sharp highs and well defined lows. As it is tightly grained wood, it does not require a finish. It is dark in color and preferred for heavier music.Ebony is more wear resistant than the other alternatives, due to its high density and strength. This is useful, if you have an aggressive style of play. Ebony is expensive and it may be difficult to find guitars with quarter swan pieces of Ebony for fingerboards, except on the very top of the line instruments. One of the issues with Ebony is that it is brittle and the fingerboards may develop some cracks over the years.
• Maple: Maple is a strong and dense wood that produces crisp and bright sound with well defined top end like Ebony. Fingerboards with Maple require finish unlike Ebony and Rosewood. Due to the light color of Maple, the fingerboard may appear dirty after some years of use due to finger oil deposition.
  

Inlay, Binding & Position Markers:

Frets 5, 7, 9 and 12, in most cases, have a dot or dots to help the player see the position of their fingers. These are known as the position markers. Instead of dots, other forms of ornamental design such as trapezoids, crosses, birds, bones etc are also used.

In some of the guitars including electric ones, even frets 3, 15, 17, 19, 21 and 24 may also have the position markers. In some fret boards, dots are inlaid on the sides along the top edge. 12th and 24th frets normally have double dots to indicate octave.  

Some fingerboards may have a strip of Ivoroid Cellulose Nitrate or any other plastic along the edge known as binding. The binding is provided to make the edges of fingerboard feel smooth to the thumb and the fingers. 

 

 

Classical guitars usually do not have any position markers or binding. Classical guitarists are always expected to know their finger position. Also, if the hand position while playing classical guitar is correct, you will never be touching the edge of the fingerboard. 

If the frets at edge of the fingerboard are properly smoothed off, there should be really no need to cover them with a binding. You may see them sometimes on less expensive guitars, but purpose there is to cover poorly seasoned wood, which may shrink, exposing fret edges. 

Twelve and Fourteen Fret Necks:

All classical and steel string guitars made till 1920s had twelve frets clear of the body. Majority of the present flat top steel string guitars have fourteen instead. 

The total frets still remain unchanged at twenty (some instruments have nineteen or twenty-one) for acoustic and eighteen or nineteen for Classical instruments. Classical guitars still continue to have twelve frets before the beginning of the body. 

Martin company introduced fourteen fret fingerboards in 1930 with their Orchestra Model (OM) series. The design was developed as per suggestions of some Banjo players, who prefer slimmer necks and more accessible frets.

These extra frets are created by reducing the upper part of the body and making the shoulders less rounded, instead of increasing the length of the neck. The upper bout is shorter for fourteen fret guitar in comparison to twelve fret ones. 

Width of the Fingerboard or Neck Width:

If you come across the term Neck width or Nut Width or Fingerboard width in the guitar specifications, these are referring to the width of the fingerboard, measured at the nut. This width varies from manufacturer to manufacturer and from model to model.

Fingerboard widens out as we move towards the sound hole. Again, the degree of widening varies between the models.

Acoustic & Classical Guitar Fingerboard Widths:

There is no standard acoustic guitar neck width and they vary between 41 mm (158” or 1.61”) to 47 mm (178” or 1.85”) for different guitars. Conversion from mm to inches may not always match exactly, as different manufacturers convert and round the numbers differently. 

Neck widths of 43 mm (11116” or 1.67”) and 44 mm (134” 0r 1.73”) are most common. Standard Martin Dreadnought model comes with 43 mm  neck width. Small differences in the neck width, of the order of (116” ), can make a significant difference in the way a guitar feels to experienced players.

Vast majority of players are not comfortable with neck widths of more than 44 mm. The degree of discomfort is more for the players who take their hand around the neck.  

Neck width of 41 to 42 mm is less common and mostly used on electric guitars. Guitars having neck width more than 47 mm are commonly referred to as wide neck guitars.

Fingerboards of 12 string guitars, naturally have to be wider to accommodate extra strings. 47 mm neck width is most common for these guitars.

Most common neck width for classical guitars is 51 mm (2”). This is due to

• Use of nylon strings, which are much bigger in gauge to steel strings
• Finger picking style of playing
• Movement of nylon strings is more because of lower tension.

Fingerboard Width and Playing Style:

Choice of the guitar neck width is largely influenced by the playing style - finger picking or flat picking. This is counter intuitive to the  common perception that it is governed by the ease of the fretting hand and the grip.

Wider necks increase the distance between the strings, allowing sufficient room for picking fingers to have a broad stroke. Classical guitars require larger stroke originating at the first knuckle joint for fuller tone and additional control.

Steel string guitar players with finger picking style use second knuckle joint that require less space for the stroke. Hence, steel string guitars have much narrower necks. Increased string distance in wider fingerboards, does not benefit flat pickers in any way. In fact, it may be of little discomfort to some players as pick has to travel extra distance.

43 mm and 44 mm wide necks provide best balance for both the styles of play for steel string guitars. 45 mm necks are more suited for finger pickers but can be comfortably used by flat pickers, as well. 47 mm necks are only suitable for finger pickers.

Fingerboard widths influences fingerboard contour, neck thickness and its contour. These factors also play a significant role in defining the overall feel of the guitar. 

In some guitars, first and sixth strings are further inside from the edge, known as insetting. In such case, the actual string spread is less than what is allowed by the nut width. So, even guitars with same neck width may have different string distances.  

Fingerboard Shape:

Majority of nylon string guitars have completely flat fingerboards. All the strings are in one plane in these instruments. This is because flat surfaces are more suited to classical playing. Flat surfaces are also found on some 12 string guitars and some recent 5 and 6 string electric basses. 

Fingerboard on most steel string guitars, however, has a slight elliptical curve along its width and is known as contoured fingerboard. The fingerboard surface may be cylindrical or conical.

• Cylindrical fingerboards have constant radius from nut end to bridge end.
• Conical fingerboard have varying radius. Radius is larger at the bridge end and reduces towards the nut.   

Radius of fingerboard in the specifications of any guitar refers to Radius of Curvature at the head stock nut, unless specifically mentioned. 

Curved cylindrical fingerboards with smaller radii (7 - 10”) are more suitable chord and rhythm playing. Instruments with large constant fingerboard radii (12 - 16“) are preferred by fast soloists.  

Conical fingerboards combine the features of small and large radius cylindrical fingerboards. In these, nut end with smaller radius is used for forming chords and bridge end with larger radius is comfortable for Solo playing and prevents fretting out. 

Fingerboard Repairs:

Unless you play six to 7 hours daily, you should not worry too much about fret board repairs. Most Ebony and even Rosewood fingerboards will last more than 30 years in this situation.

However, if you play for many hours per day in aggressive style style or keep big fingernails, some pits and cracks may appear after 10 to 15 years. These can be repaired by use of dust of the concerned wood mixed with epoxy resin. If the damages are more, even fingerboard replacement is a pretty routine repair job. 

Frets:

Fret is a raised element in the form of a metal strip extending across the full width of the fingerboard. Strings are pressed against the frets to produce clear notes. Each fret represent one semitone. 

Fret Materials

• Most of the frets are made up of Nickel Silver. This is a hard Nickel - Steel alloy. Nickel Silver is the industry name of this alloy, in spite of the fact that it does not contain any silver. Percentage of Nickel may vary in the alloy and governs the hardness of the fret. While, most of the frets are made with 18% Nickel, 12% Nickel frets are also available.    
• Inexpensive and vintage guitars have brass frets. Brass is soft and wears down quicker than other options.
• Some manufacturers offer stainless steel or other similar metal frets. These frets are hard and smooth with virtually non existent wear. If you play aggressively and require regular re-fretting, it is better to go in for stainless steel frets. But, harder materials are difficult to work with and require hard and expensive tools, making repairs costly.
• Evo, an alloy of Copper, Tin, Nickel and Iron is also used to make frets. Its hardness is between that of Nickel Silver and Stainless steel. So, it is easier to work with and less expensive to re-fret.

Fret Construction:

Fret or Fret wire, as it is called, is made up of two components, the Crown and the Tang. 

• Crown is also known as the bead. This is visible or the exposed part of the fret on the fingerboard. While fretting, you press the string against the crown.
• Tang is the metal tongue which holds the fret into the fingerboard with the help of protrusions to grip the wood. These work like row of hooks and are called “barbs” or “dimples” or “studs”.
• Four elements completely define the style of the fret. Two of them specify crown and balance two define the tang. These are the width and height of the crown, the size of the studs and the depth of the tang. Size and shape of these elements are varied to suit different types of guitars and playing preferences.
• Luthiers make fine slots in the fingerboard at required intervals. Tang are placed in these slots. Fret wire is drawn little longer than fingerboard width and hammered in. Side protrusions are then cut and filed. Some manufacturers use epoxy glue in the grooves to seat frets. This makes the guitar harder to re-fret and is not recommended.

Crown Width & Height:

Crown width varies between 0.053” (ultra narrow) to 0.115” (jumbo), Wider crowns produce produce strong tones. However, their wear can produce very pronounced intonation affects. Narrow frets wear down faster, but have lower intonation drifts.

Crown height may vary between 0.032” (short) to 0.060” (tall). Taller frets have longer life. If you have stronger grip, whereby you grip neck tightly or frequently use a Capo, go fall shorter crowns. This is because the strings will be pulled sharply as you play. Shorter or low frets wear out faster and need to be replaced often. 

A fret is termed as medium, if it has medium width and height, around 0.085” x 0.045”. These are found on most Acoustic guitars. Jumbo frets have dimensions of 0.115” x 0.05” (+), where (+) sign means more than the given dimension. These are used on most Electric guitars and some Acoustic guitars with Electric guitar feel. 

Most contemporary Acoustic guitars have medium frets. Gibson used low jumbo frets on their older instruments. These frets have dimensions of 0.110” x 0.035” and were also called low “speed” frets. These were used mostly on Electric instruments. 

These are sometimes used for replacement of individual high frets on guitars having otherwise worn out frets. 

Stud Size and Tang Depth:

These are also referred to as the Tang width and depth in many literature. They can have different combinations of dimensions independent of crown. In older guitars, before 1930, tang without crowns were used and were called bar frets. Crowns form a T-shape with Tangs and hence, these are also known as T-Frets.

Dimensions of Tang have a big impact on the guitar neck. Use correct size tangs if you have to do re-fretting for any reason. 

During re-fretting, slightly thicker gauge tangs are used, This is because the slots, housing the frets, get enlarged by pulling out old frets. Wider gauge tangs can bend the neck into a reverse warp, as they expand the fingerboard. This can however be used as a remedy for forward warp in a neck.

If the tang depth and width are too shallow or narrow for the slots, they will not seat properly in the fingerboard and will lift in adverse weather conditions. This will result in uneven frets with dead or buzzy notes. 

Fret Replacements  

Pressing strings against the frets results in subtle wear of the frets due to friction between the two. The wear is not even along the fret and cause pitting and dents, which is more pronounced under the unwound strings. Frequent use of Capos can also cause a lot of wear. Flattening of crowns cause intonation and string rattle issues.

Minor wear is repaired using file and sandpaper. First, they are filed to equal heights, resulting in flat crowns. Then, they are re-crowned by removing metal from their sides,  making them narrower. 

Multiple repairs reduce crown dimensions and it is time to go for re-fretting, when 

1. Crown height is below 0.038” and crown has pits and dents.
2. You have to apply too much pressure to string against a very low fret, resulting in a very acute angle. This results in buzz against the next fret.  

One quick fix solution to the above problem is to file the next fret, but this results in a domino effect leading to filing of all frets one by one.