Denim fabric is a type of fabric that started to be used centuries ago but still does not lose its popularity. The most distinctive feature of denim fabric is that the warp yarn is dyed with indigo dye, and the weft yarns are not dyed, ie white. Denim fabric is popularly called blue jeans. However, blue jeans is the name given to all clothes made of denim fabrics, especially trousers. Denim fabric is a coarse, durable and useful fabric used in the production of sportswear and blue jeans, and generally those produced from a single layer of 100% cotton yarns are preferred. Classic denim fabric is produced with the way of twill weave called gabardine. Left (S) way twill fabrics are softer than right hand (Z) twill fabrics. Generally, yarns used in denim fabrics are Z-twisted. If the preferred weave is left (S) way twill weave, since the twist on the yarn and the knitting will be in reverse direction, the tension caused by the twist on the yarn decreases and the twist is opened. This causes the woven fabric to be soft. The reason why right (Z) way twill weave is preferred is that it makes less stretch. Due to the density of warp threads on the surface of the fabric both in terms of knitting requirement and density, the color of the warp thread dominates the fabric appearance. Denim fabrics are produced by following a different process than other classical woven fabric productions due to the indigo dye substance. This difference usually manifests itself in the weaving preparation department. Threads are dyed with indigo dye in rope or warp, sized and sent to weaving.
Indigo dyestuff, known as "living color", is produced synthetically today and enables the product dyed with this dye to change color and whiten over time and with washing. In denim weaving, mostly rotor-spun (OE) and less often ring-carded yarn are preferred. Apart from these, there are also denim fabrics using fancy and special yarns. There are many types of denim that are called by giving different names in the market. Some of these are; Natural Denim is a fabric whose warp and weft yarns are not dyed, Antique Denim; It is a denim fabric woven in shuttle looms with ring yarn weft and warp yarns at the end of the nineteenth century. Today, fabrics with the same effect are very difficult to find. Fish Net Denim: a fabric whose warp and weft are woven from slub ring yarn. Stretch / Lycra Denim: It is a fabric woven with cotton, weft yarns consisting of the twist of elastic lycra yarns and warp yarns produced from 100% cotton yarn. Ounce / yrd2 is used as weight unit for the definition of denim fabrics. According to the metric system, its equivalent is 1 ounce / yrd2 = 33.91 g / m2. The unit weights of denim fabrics are between 3.5 - 16.5 oz / yd2 (118 - 560 g / m2) depending on the areas of use. The weight unit oz (ounce) used in denim fabrics also helps in grouping the fabrics and determining the area of use. Examples of these are the following group: 4.5 oz - 7.5 oz Denim: It is the denim fabric used in shirts. 9 oz - 13.5 oz Denim: Denim fabric used in summer trousers. 14 oz - 15 oz Denim: Denim fabric used in pants and coats. Denim fabrics are expressed in the world with names such as "jeans", "blue-jeans", "jeans wear" and "sports wear". Whereas in Turkey denim fabric "jeans", and the pants sewn from denim are called "blue jeans". Separate definitions and explanations for all of them have been made in order to eliminate this confusion in the definitions of denim. The term jeans: Derived from the worn blue trousers worn by Genoa harbor sailors and other industrial workers on a daily basis. Jeans are called heavy cotton fabrics with D 2/1 Z or D 3/1 Z twill weave dominated by warp or weft yarns, woven with solid yarns and dyed in different colors. Blue-jeans: The warp yarns are dyed blue with indigo dye, the weft yarns are unpainted, D 2/1 Z or D 3/1 Z twill weave, strong, heavy cotton fabrics and trousers made of these fabrics. Jeans-wear: It is the clothing made of jeans type fabrics such as pants, shirts, skirts, vests and jackets. Sports Wear: Any type of clothing known as sportswear, casual wear or leisure clothing.