Denim is a special kind of fabrics. It is the basic material for the production of jeans.
The name "denim" is an anglicized short form of "Serge de Nîmes" (fabric from Nîmes, a town in France, where this kind of fabric was produced). This fabric from Nîmes was introduced into the US by Levi Strauss who used it to produce solid trousers which later became known as jeans.
Denim is a woven fabric of the twill type in which the weft thread passes under two or more warp threads with an offset of one step between adjacent rows so that a diagonal ribbing of the fabric is achieved. The fabric is generally made with 100% cotton. Some sorts of denim, however, also comprise an elastic component such as spandex. This type of denim is called stretch denim.
Typically, the warp threads are dyed with an indigo dye in the distinctive blue color of "blue jeans", while the the weft threads are left white. In the garment produced from this fabric, the dyed warp-side faces outwards and shows the color whereas the inside shows the white weft threads.
The weft threads, however, are not thourougly dyed, but left white in their core. By abrasion during wearing and washing, the white core appears under the dyed surface so that the color of the fabric fades. This gives used garments made from denim, especially jeans, a unique look. Such a used look, however, may also be achieved by different washings during the production, from a simple stone-wash process up to the extensive three days treatment conducted by Diesel for their Blue Eyecons jeans.
Beside jeans, examples for clothing by Diesel made from denim include jackets, vests, shirts, jumpsuits, shorts, and skirts. Examples for accessories by Diesel made from denim include caps, shoes, bags, wallets, bracelets, and watch straps. Diesel also uses denim patches applied onto other garment such as T-shirts or even eyewear.
Based on denim, Diesel has developed a new fabric in which the properties of denim and jersey are combined: the Jogg Jeans.