White label records are vinyl records with plain white labels attached. There are several variations each with a different purpose. Variations include test pressings, white label promos, and plain white labels.
Test pressings, usually with test pressing written on the label, with catalogue number, artist and recording time or date, are the first vinyl discs made at the factory. They are produced in small quantities (usually under five copies) to evaluate the quality of the disc before mass production begins.
In the U.S., the traditional term white label promo (often abbreviated as WLP) refers to a promotional pressing with a label that has mostly the same text and label logo/artwork as the commercial label, but with a white background instead of the color or artwork found on the commercial pressings.
Plain white label promotional recordings were produced in larger quantities by bigger record labels, often containing a biography of the band, to distribute as demonstration discs ("demos") to music distributors, and radio stations in order to assess consumer opinion.
Today, white labels discs are commonly used to promote new artists or upcoming albums by veteran artists. In some cases white labels are issued to conceal artist identities (examples of this include songs by Traci Lords and La Toya Jackson, whose record companies issued white labels so that DJs would have no pre-conceived notions about the music just by seeing who the artist was). Many dance music producers press copies of white labels in order to test crowd response in dance clubs to their own musical productions.
Today, white labels are usually produced in small amounts (fewer than 300) by small record companies or DJs and are most popular with house music and hip-hop music DJs. In the early 1990s, hardcore techno and house artists created tracks in home or local studios and had five-hundred or a few thousand singles pressed on 12" white labels, which were easy to sell at dance music record stores.
Steve Beckett of Warp Records recalls that "shops would take fifty white labels off you for five pounds each, no problem. Dance music was all imports, then people in Britain started doing it for themselves, and their tracks started to get better than the tunes in America."  Record labels like Warp, and Shut Up and Dance, were begun as white-label enterprises, providing cutting-edge dance music to pirate radio stations and music stores.
Many white labels contain unauthorized remixes or tracks that are not yet licensed or released (also called "bootlegs"). White labels are referred to as "promos" (short for "promotional copies") that many top-name DJs receive and play weeks or months prior to the day of general release to the public. As artists using samples pay high fees for the privilege of such, they must be able to gauge the market potential of their tracks prior to approval. Recently, smaller promo services offer record companies a more economical means of distribution although these companies may not have the means to properly protect releases from illegal copying.
The industry itself seems to be aware of this necessity and white labels are commonly accepted as a necessary evil within the industry, which has only prosecuted a small number of those artists using white labeled pressings of uncleared samples and compositions.