A fretboard (or fingerboard on fretless instruments) is a thin, long strip of material, usually wood, that is laminated to the front of the neck of a guitar. The strings run over the fretboard, between a nut and a bridge. A player presses strings down to the fretboard to change the vibrating length, varying the pitch and picks notes by the other hand. Notes can be played solely by the fretting hand using hammer-ons.
On modern guitars, frets are typically made of metal. Frets let the player stop the string consistently in the same place, which enables the musician to play notes with the correct intonation. Frets do not obscure string vibrations as much as fingers alone on an unfretted fingerboard.
Unfretted fingerboards provide more control over detailed changes in pitch than fretted boards, but are harder to master.
Vigier Excalibur Surfreter Special fretless guitar.
Some fingerboards may also be, though uncommon, a hybrid of fretted and unfretted fingerboards.
Frets can be marked by various inlays to make navigating easier.
Over time, strings wear frets down, which can cause buzz and decrease of the sound fullness. Fixing this occasionally requires replacing the frets — but more often they just need "dressing". In fret dressing, a luthier levels and polishes the frets, and crowns (carefully rounds and shapes) the ends and edges. Stainless steel guitar frets may never need it, because of the density of the material.
Frets should be carefully and accurately aligned with the fingerboard in order to prevent intonation problems and permanent detuning. The best way of discovering the source of a buzz and detuning problems is to measure the level of the frets. A straight edge positioned on the neck in the "lie" of one of the strings should show nearly leveled frets. (But there should be a slight relief to compensate for the elliptical shape of the vibrating strings.)
Typically, the fingerboard is a long plank with a rectangular profile. On the guitar, mandolin, ukulele, or similar plucked instrument, the fretboard appears flat and wide but may be slightly curved to form a cylindrical or conical surface of relatively large radius compared to the fretboard width. The radius quoted in the specification is the radius of curvature of the fretboard at the head nut.
The length, width, thickness and density of a fingerboard can affect timbre. Most fretboards can be specified by the following parameters:
- w1 — width at nut
- w2 — width at half of scale length (usually the 12th fret)
- h1 — profile height (thickness) at nut
- h2 — profile height (thickness) at half of scale length
- r — radius (may vary in different parts of fretboard)
Fretboard profile from nut to bridge.
Types of fretboard:
- Flat. Nut and bridge are flat. The strings are all on one level, and the instrument does not have a radius
- Cylindrical. The fretboard has the same radius at the nut and at the bridge.
- Conical. The fingerboard has a varying radius, usually linearly progressing from the nut to the bridge.
- Compound. It's not strictly conical, has a curved nut and linear bridge.
Classical guitars, some 12-string guitars, banjos, and a few steel stringed acoustic guitars have flat fretboards. Almost all other guitars have some curvature. However, some recent five and six-string electric basses have flat fingerboards.
Some guitar players prefer smaller radius fretboards (7.25–10") because they are more suitable for chord and rhythm playing, while larger radius fretboards (12"-16" and up to flat) are more convenient for fast soloing. Compound and conical fretboards try to merge both these features. The nut end of the fretboard has a smaller radius to ease in forming chords. The bridge end of the fretboard has a larger radius to make soloing more comfortable and prevent "noting out" ("fretting out"), in which a string comes in contact with a higher fret during bends.
Main article: Scalloping.
A fretboard can be scalloped by "scooping out" the wood between each of the frets to create a shallow "U" shape. The result is a playing surface wherein the players' fingers come into contact with the strings only and don't touch the fingerboard.
The scalloped fingerboard of Yngwie Malmsteen Stratocaster.