A dub plate used to refer to an acetate disc used in mastering studios to test recordings before mass producing the vinyl.
via Reggae Zine UK
Caribbean battle music in DJ vs DJ soundclashes took on the dubplate to create exclusive remixes to popular songs usually with the artist shouting out the name of the Sound System playing the track.
Nowadays, digital recording technology has eliminated the need for any type of physical format to create a dub, but the concept is bigger than ever.
Dub cutters can set up shop anywhere from an artist's hotel room to a street corner, to a barbershop, and have them fill in the blanks with their name on a song.
This practice is especially common in Caribbean musics like dance hall, and soca. Artists can make a lot of side money by selling these on the spot remixes, and DJ's and sound systems get that money back by filling parties.
For daily examples of dubs tune into Mixx 96.1 FM or log on to 96mixx.com.