Guitar pick in the context of Nylon

The guitar is a stringed musical instrument that is usually fretted (with some exceptions) and typically has six or twelve strings. It is usually held flat against the player's body and played by strumming or plucking the strings with the dominant hand, while simultaneously pressing selected strings against frets with the fingers of the opposite hand. A guitar pick may also be used to strike the strings. The sound of the guitar is projected either acoustically, by means of a resonant hollow chamber on the guitar, or amplified by an electronic pickup and an amplifier.

The guitar is classified as a chordophone, meaning the sound is produced by a vibrating string stretched between two fixed points. Historically, a guitar was constructed from wood, with its strings made of catgut. Steel guitar strings were introduced near the end of the nineteenth century in the United States, but nylon and steel strings became mainstream only following World War II. The guitar's ancestors include the gittern, the vihuela, the four-course Renaissance guitar, and the five-course baroque guitar, all of which contributed to the development of the modern six-string instrument.

A plectrum is a small flat tool used for plucking or strumming of a stringed instrument. For hand-held instruments such as guitars and mandolins, the plectrum is often called a pick and is held as a separate tool in the player's hand. In harpsichords, the plectra are attached to the jack mechanism.

An acoustic guitar is a musical instrument in the string family. When a string is plucked, its vibration is transmitted from the bridge, resonating throughout the top of the guitar. It is also transmitted to the side and back of the instrument, resonating through the air in the body, and producing sound from the sound hole. While the original, general term for this stringed instrument is guitar, the retronym 'acoustic guitar' – often used to indicate the steel stringed model – distinguishes it from an electric guitar, which relies on electronic amplification. Typically, a guitar's body is a sound box, of which the top side serves as a sound board that enhances the vibration sounds of the strings. In standard tuning the guitar's six strings are tuned (low to high) E₂ A₂ D₃ G₃ B₃ E₄.

Guitar strings may be plucked individually with a pick (plectrum) or fingertip, or strummed to play chords. Plucking a string causes it to vibrate at a fundamental pitch determined by the string's length, mass, and tension. (Overtones are also present, closely related to harmonics of the fundamental pitch.) The string causes the soundboard and the air enclosed by the sound box to vibrate. As these have their own resonances, they amplify some overtones more strongly than others, affecting the timbre of the resulting sound.

Celluloids are a class of materials produced by mixing nitrocellulose and camphor, often with added dyes and other agents. Once much more common for its use as photographic film before the advent of safer methods, celluloid's common present-day uses are for manufacturing table tennis balls, musical instruments, combs, office equipment, fountain pen bodies, and guitar picks.

A fingerpick is a type of plectrum used most commonly for playing lap steel guitar and bluegrass style banjo music. Hawaiian steel guitar players invented them to gain a more substantial sound from their instruments. The National Finger Pick was patented on July 20, 1928, by George Beauchamps and John Dopyera. Most fingerpicks are composed of metal or plastic (usually Celluloid or Delrin). Unlike flat guitar picks, held between the thumb and finger and used one at a time, fingerpicks clip onto or wrap around the end of the fingers and thumb; thus, one hand can pick several strings at once. Generally, three are used: one for the thumb, middle, and index fingers. Fingerpicks worn on the thumb are called "thumbpicks". Some players use a plastic thumbpick while using metal fingerpicks. Fingerpicks come in various thicknesses to accommodate different musicians' styles of playing. Thin picks produce a quieter, more delicate sound, while thick picks produce a heavier sound. However, thumbpicks come in various styles and employ different materials, as with standard plectrums.

Fingerpicks are also used by guitar, Hawaiian guitar, lap steel, autoharp, pedal steel guitar and Dobro players. Fingerpicks generally take quite some time to adapt to, even for people who come from the more common (bare fingers with or without fingernails) fingerstyle techniques. Tone-wise, they are the most similar to standard guitar picks, offering a more consistent sound.

A Reuleaux triangle [ʁœlo] is a curved triangle with constant width, the simplest and best known curve of constant width other than the circle. It is formed from the intersection of three equally sized circular disks, each centered on the boundary of the other two. Constant width means that the separation of every two parallel supporting lines is the same, independent of their orientation. Because its width is constant, the Reuleaux triangle is one answer to the question "Other than a circle, what shape can a manhole cover be made so that it cannot fall down through the hole?"

They are named after Franz Reuleaux, a 19th-century German engineer who pioneered the study of machines for translating one type of motion into another, and who used Reuleaux triangles in his designs. However, these shapes were known before his time, for instance by the designers of Gothic church windows, by Leonardo da Vinci, who used it for a map projection, and by Leonhard Euler in his study of constant-width shapes. Other applications of the Reuleaux triangle include giving the shape to guitar picks, fire hydrant nuts, pencils, and drill bits for drilling filleted square holes, as well as in graphic design in the shapes of some signs and corporate logos.

Flatpicking (or simply picking) is the technique of striking the strings of a guitar with a pick (also called a plectrum) held between the thumb and one or two fingers. It can be contrasted to fingerstyle guitar, which is playing with individual fingers, with or without wearing fingerpicks. While the use of a plectrum is common in many musical traditions, the exact term "flatpicking" is most commonly associated with Appalachian music of the American southeastern highlands, especially bluegrass music, where string bands often feature musicians playing a variety of styles, both fingerpicking and flatpicking. Musicians who use a flat pick in other genres such as rock and jazz are not commonly described as flatpickers or even plectrum guitarists. As the use of a pick in those traditions is commonplace, generally only guitarists who play without a pick are noted by the term "fingerpicking" or "fingerstyle".

Probably starting around 1930, flatpicking in American music was developed when guitarists began arranging old-time American fiddle tunes on the guitar, expanding the instrument's traditional role of rhythm guitar accompaniment with an occasional run on the bass strings. Although early guitarists such as Riley Puckett used a thumb pick to emphasize bass notes, this part of the style was adapted into flatpicking.