An acetate disc, also known as a test acetate, dubplate

Dubplate

A dubplate is an acetate disc – usually 12, 10, or 7 inches in diameter – used in mastering studios for quality control and test recordings before proceeding with the final master, and subsequent pressing of the record to be mass-produced on vinyl. The "dub" in dubplate is an allusion to...

(a term from Jamaican reggae culture, now also applied to individually recorded discs of solid plastic), lacquer (a technically correct term preferred by engineers in the recording industry), transcription disc (a special recording intended for, or made from, a radio broadcast) or instantaneous disc (because it can be played immediately after recording without any further processing), is a type of gramophone record

Gramophone record

A gramophone record, commonly known as a phonograph record , vinyl record , or colloquially, a record, is an analog sound storage medium consisting of a flat disc with an inscribed, modulated spiral groove...

, a mechanical sound storage medium, widely used from the 1930s to the late 1950s for recording and broadcast purposes and still in limited use today.

Unlike ordinary vinyl records, which are quickly formed from lumps of plastic by a mass-production molding process, a so-called acetate disc is created by using a recording lathe to cut a sound-modulated groove into the surface of a special lacquer-coated blank disc, a real-time operation requiring expensive, delicate equipment and expert skill for good results. They are made for special purposes, almost never for sale to the general public. They can be played on any normal phonograph

Phonograph

The phonograph record player, or gramophone is a device introduced in 1877 that has had continued common use for reproducing sound recordings, although when first developed, the phonograph was used to both record and reproduce sounds...

 but will be degraded by wear much more quickly than vinyl. Some acetates are highly prized for their rarity, especially when they contain unpublished material.

Acetates are typically produced by dubbing from a master

Master recording

A multitrack recording master tape, disk or computer files on which productions are developed for later mixing, is known as the multi-track master, while the tape, disk or computer files holding a mix is called a mixed master.It is standard practice to make a copy of a master recording, known as...

 tape recording. By electroplating

Electroplating

Electroplating is a plating process in which metal ions in a solution are moved by an electric field to coat an electrode. The process uses electrical current to reduce cations of a desired material from a solution and coat a conductive object with a thin layer of the material, such as a metal...

 the acetate master, stampers (special moulds) can be created, which in turn are used to press large quantities of regular vinyl records. Acetates are also used for testing the quality of the tape-to-disc transfer. Historically, they were also a favored medium for use in comparing different takes or mixes, and for getting preview copies of impending new releases into the hands of important disc jockeys.

Physical characteristics

Although once produced in a wide range of sizes (from less than 7 to more than 16 inches in diameter) and sometimes with glass core discs, the examples most commonly encountered today are 10 or 12 inches in diameter and consist of an aluminum core disc coated with black nitrocellulose lacquer. Blank discs were traditionally produced in several different grades, with the best and costliest grade featuring the sturdiest core, the thickest coating and the most perfectly flawless mirror-like surfaces. These top-quality blanks were intended for cutting the master discs which would be processed into metal parts for pressing

Record press

A record press is a machine for manufacturing vinyl records. It is essentially a hydraulic press with a closing force of 100 tons and is fitted with moulds. Labels and a vinyl pattie are placed in the mould cavity while the moulds are being steam-heated with an ideal steam pressure of 140-170psi...

 ordinary records. Second-quality blanks were considered adequate for non-critical uses such as tests and demo discs. Lower-grade blanks were formerly made for home use by amateurs and may be very thin and flexible, may have a cardboard rather than a metal or glass base, and may have noticeably dull or slightly orange-peel-textured surfaces. Regardless of grade, there is almost always at least one extra "pilot hole" in the label area, meant to be engaged by a special pin which prevents the disc from slipping on the turntable during the recording process. Pilot holes are often hidden by labels applied after the recording was made, but can usually be detected by careful inspection of the label or by holding the disc up to a light bright enough to penetrate the labels.

Uses

Acetates have not always been used solely as a means of checking the quality of a disc recording. They were widely used before magnetic tape was invented and in the modern era they are used by dance music DJs (acetates were also used extensively in Jamaica by sound system operators in the late 1940s - 50s.). Because of their limited useful lifetime, acetates were often used as "demos" of new recordings by artists and record labels.

Recording

From the 1930s to the late 1940s, before the introduction of magnetic tape

Magnetic tape

Magnetic tape is a medium for magnetic recording, made of a thin magnetizable coating on a long, narrow strip of plastic. It was developed in Germany, based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders...

, recordings were normally made directly to acetate discs (see direct to disc recording

Direct to disc recording

Direct to disc recording refers to sound recording methods which bypass the use of magnetic tape recording and directly onto disc master; and record albums made using this process....

). Acetates were also used as a storage medium for radio commercials; since commercials only run for a limited time, it didn't matter if the disc wore out relatively quickly. During the early tape era (1950s, primarily), acetate discs and portable disc recorders competed with magnetic tape as a location-recording medium, both for broadcast and semi-pro use. Acetate discs inherently are less durable than magnetic tape, and also cannot be physically edited (cut and spliced).

Gramophone disc mastering

In preparation for a record pressing, acetates are used for quality control prior to the production of the stampers, from which retail copies of the record will be pressed. The purpose of the test acetate(s) in the mastering process is to allow the artist, producer, engineer, and other interested parties to check the quality of the tape-to-disc recording process and make any necessary changes to ensure that the audio fidelity of the master disc will be as close as possible to that of the original master tape. The actual stampers can be made either from normal acetates, or from a DMM disc (see Direct Metal Mastering

Direct Metal Mastering

Direct Metal Mastering is a vinyl record manufacturing technology by TELDEC. Records manufactured with this technology are often marked by a "DMM" logo on the outer record sleeve....

).

Dance music

In the dance music

Electronic dance music

Electronic dance music is electronic music produced primarily for the purposes of use within a nightclub setting, or in an environment that is centered upon dance-based entertainment...

 world, DJ

Disc jockey

A disc jockey, also known as DJ, is a person who selects and plays recorded music for an audience. Originally, "disc" referred to phonograph records, not the later Compact Discs. Today, the term includes all forms of music playback, no matter the medium.There are several types of disc jockeys...

s cut new or otherwise special tracks on acetates, in order to test crowd response and find potential hits. This practice started as early as in the 1960s in Jamaica, between so called sound systems, as a way of competing and drawing bigger crowds. These discs are known as dubplates. But the word "dubplate" can interchangeably mean an actual disc or just the music/recording, which can be on any other medium (e.g. CD). Dubplates were used by reggae soundsystems worldwide, and later adopted by producers of various dance music genres, most notably Drum and Bass

Drum and bass

Drum and bass is a type of electronic music which emerged in the late 1980s. The genre is characterized by fast breakbeats , with heavy bass and sub-bass lines...

 and Dubstep

Dubstep

Dubstep is a genre of electronic dance music that originated in south London, England. Its overall sound has been described as "tightly coiled productions with overwhelming bass lines and reverberant drum patterns, clipped samples, and occasional vocals"....

. Trading dubplates between different DJ's is an important part of DJ culture. Actual acetate dubplates are declining in popularity, and being increasingly replaced by CD's and vinyl emulation software

Vinyl Emulation Software

Vinyl emulation software allows the user to physically manipulate the playback of digital audio files on a computer using the turntables as an interface, thus preserving the hands-on feel of deejaying with vinyl while allowing playback of audio recordings not available in phonograph form...

 because of weight, durability and overall cost.

Material and packaging

Despite their name, most acetate discs do not contain any acetate

Acetate

An acetate is a derivative of acetic acid. This term includes salts and esters, as well as the anion found in solution. Most of the approximately 5 billion kilograms of acetic acid produced annually in industry are used in the production of acetates, which usually take the form of polymers. In...

. Instead, most are an aluminum disc

Aluminum disc

An aluminium disc is a disk made out of aluminium and is used as a transcription disc in magnetic recording media, specifically early radio recordings...

 with a coating of nitrocellulose lacquer. (Glass was also used during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, when aluminum was in short supply.) This production process results in a disc that is different in many ways from the vinyl records sold to customers at retail. Whereas vinyl records are light and semi-flexible, acetates are rigid and somewhat heavier. More significantly, the thin coating of lacquer on an acetate is much more susceptible to wear; the playback head of a stylus

Magnetic cartridge

A magnetic cartridge is a transducer used for the playback of gramophone records on a turntable or phonograph. It converts mechanical vibrational energy from a stylus riding in a spiral record groove into an electrical signal that is subsequently amplified and then converted back to sound by a...

 quickly damages the grooves of the record such that after only a relatively few number of plays the audio quality is noticeably degraded. This is not a problem, however, since acetates are only test recordings and are not designed to be able to stand the test of time.

Acetates typically come in two sizes: 10" discs for singles and 12" discs for albums. The record's sleeve is typically nothing more than a generic cover from the manufacturing company and the disc's label is similarly plain, containing only basic information about the content (title, artist, playing time, etc.), which is usually typed but is often just hand-written.

Value

Due to their rarity, some acetates can command high prices at auction. Brian Epstein

Brian Epstein

Brian Samuel Epstein , was an English music entrepreneur, and is best known for being the manager of The Beatles up until his death. He also managed several other musical artists such as Gerry & the Pacemakers, Billy J. Kramer and the Dakotas, Cilla Black, The Remo Four & The Cyrkle...

's collection of Beatles acetates fetched between $1,000 and $10,000 per disc. An acetate from The Velvet Underground

The Velvet Underground

The Velvet Underground was an American rock band formed in New York City. First active from 1964 to 1973, their best-known members were Lou Reed and John Cale, who both went on to find success as solo artists. Although experiencing little commercial success while together, the band is often cited...

, containing music that would later appear on their first album, The Velvet Underground & Nico, sold on eBay

EBay

eBay Inc. is an American internet consumer-to-consumer corporation that manages eBay.com, an online auction and shopping website in which people and businesses buy and sell a broad variety of goods and services worldwide...

in 2006 for $25,200.