Slipknot is an American heavy metal band from Des Moines, Iowa, formed in 1995. Slipknot consists of nine members, the current band members are Sid Wilson, Joey Jordison, Paul Gray, Chris Fehn, Jim Root, Craig Jones, Shawn Crahan, Mick Thomson, and Corey Taylor. Each member of the band wears a unique mask.

Slipknot formed in 1995 and underwent several line-up changes following the independent release of their first demo Mate. Feed. Kill. Repeat. in 1996. That album featured original lead vocalist, Anders Colsefini. Their self-titled, major label debut, Slipknot, was released in 1999, featuring permanent new lead vocalist, Corey Taylor, and was followed by Iowa in 2001 and Vol. 3: (The Subliminal Verses) in 2004. On August 25, 2008, the band returned to release their fourth studio album, All Hope Is Gone, which debuted at the top spot on the Billboard 200 charts. The band has released three DVDs, including Disasterpieces, which was certified quadruple-platinum in the United States.

The band is known for its attention-grabbing image: the members wear matching jumpsuit uniforms, and each one has a unique mask. In the past, their jumpsuits have featured large UPC barcodes printed on the back and sleeves, which are identical and render the same barcode number to the barcode on their first demo, Mate. Feed. Kill. Repeat. Aside from their real names, members of the band are referred to by numbers zero through eight.

With each new album, Slipknot has used new masks and coveralls. The masks haven't changed dramatically with the release of their second and third albums, as the masks are more of an extension of what they previously were. Jordison addressed the issue in an interview in 2004, stating that the change in masks are to show growth and difference within age. During the music video and live performances of their single "Vermilion" the band change their respective masks to death masks made from casts of their own faces. Also in 2004, Gray claimed that the special effects company Screaming Mad George made their masks from their third album cycle, and pictures of the band's masks from their second album cycle can be found on the SMG website.

The masks have been subject of much criticism, generally thought of as a gimmick to try sell their product. The band strongly objects to these claims, proclaiming that the masks are used to draw the attention away from themselves and put it on the music. Several members have said how the masks are a visual representation of how the music makes them feel and how they put the members in an animal-like mentality.

All Information taken from Wikipedia.org