Denim Fabrics – properties and types

Denim Fabric Construction

Denim is made from rugged tightly woven twill in which the weft passes under two or more warp threads. Lengthwise, the yard is dyed with indigo or blue dye; horizontal yarns remain white. The yarns have a very strong twist to make them more durable, but this also affects the denim’s colour.

The yarns are twisted so tightly that indigo dye usually colours only the surface, leaving the center of the yarn white. The blue strands become the threads that show on the outside of your denim and the white are the ones that make the inside of your denim look white. This produces the familiar diagonal ribbing identifiable on the reverse of the fabric. Through wear, the indigo yarn surface gives way, exposing the white yarn underneath which causes denim to fade. Jeans are basic 5 pocket pants or trousers made from denim.

Denim is an indigo-dyed cotton twill fabric in which the weft passes under two or more warp fibers. The term derives from ‘Serge De Nimes’, the French city where it was produced; but denim and Serge De Nimes are in fact different fabrics.

Two words come from the name of a sturdy fabric called serge, originally made in Nimes, France. Originally called serge de Nimes (the fabric of Nimes), the name was soon shortened to denim (de Nimes). Denim was traditionally coloured blue with natural indigo dye to make blue Jeans, though “Jean” then denoted a different, lighter cotton textile, the contemporary use of jean comes from the French word for Genoa, Italy, where the first denim trousers where made. Jeans transcend age, economic and style barriers. But jeans themselves have reached iconic status.

Jeans based on cuts and washes:

Low-rise, ultra-low-rise, Boot-cut, Flare leg, Stone-washed, Dark, distressed jeans.

Jeans based on body types:

Slim body, Curvy body, Athletic body, Full-figured body types.

Type of Denim

1. Black-Black denim

   Denim where the warp yarn is black instead of blue and which is also dyed black after weaving. This makes the jeans truly black rather than grey.

2. Bull Denim

   A 100% cotton tough fabric, Bull Denim is constructed of coarse, often slubby yarns with 3×1 twill weaving pattern. It is extremely durable and soft. The fabric is perfect for slipcovers, upholstery, toss pillows, covering headboards, and cornices.

3. Coloured Denim

   Coloured Denim is manufactured by dyeing with sulfur than using traditional Indigo dye. A combination of colour finishing is achieved with sulfur dyeing.

4. Cotton Serge Denim

   Cotton Serge Denim ad manufactured from 100 percent cotton in a diagonal pattern. The Cotton Serge Denim is well known for its sturdy and resilient features.

5. Crushed Denim

   Crushed Denim are fabrics that look permanently wrinkled by weaving it with over twisted weft yarn and shrinks when washed. The result can be made even more visible by stone washing and/or bleaching.

6. Dual Ring-Spun Denim

   Dual Ring-Spun Denim is also called “ring X ring”. Signifies a denim weave in which both the warp and weft threads are made of ring-spun yarn. It creates a much softer and textured hand than both open-end and regular (single) ring-spun denim. Due to higher production costs, it is usually only used by higher end, premium denim labels.

7. Ecru Denim

   Generally, the denim fabrics are dyed with Indigo colour and Ecru Denims are the one that is not been dyed and has the look of a natural hue of cotton.

8. Natural Denim

   A type of ring-ring denim naturally uneven in warp and weft.

9. Open End Denim

   Open End or OE Spinning was introduced in the 1970s, reducing cost by omitting several elements of the traditional spinning process. The cotton fibres are ‘mock twisted’ by blowing them together. Open End denim is bulkier, coarser and darker, because it absorbs more dye, and wears less well than Ring Spun denim.

10. Over Twisted Denim

    Over Twisted Denim is made from yarn that is over twisted, giving the fabric a particular crinkled surface.

11. Pinto Wash Denim

    A product of Cone Mills, USA; said to be the first bleached denim. In 1969, in Greensboro, North Carolina, a hurricane flooded local Cone Mills plants and warehouses. Millions of yards of denim were soaked with water and had to be dried immediately to avoid mildewing. It seemed a catastrophe, but a Cone Mills merchandiser in the New York office came up with an idea: run the fabric irregularly through a solution to remove the dye and give the denim a faded and mottled appearance. Designers, manufacturers and young consumers all jumped on the new product, making Pinto Wash Denim an instant success.

12. Polycore Denim

    Often found in replica jeans, offers the best mix of the strength of the polyester core and vintage aesthetic of cotton top thread layer.

13. Printed Denim

    Printed Denim are fabrics printed with a pattern such as batik, stripe or floral, for example-often in contrasting colours and aimed at a very young market.

14. Raw/Dry Denim

    Raw/Dry denim are fabrics that haven’t gone through the pre-wash process, therefore they are pretty stiff on the first time use. It takes a few weeks of regular wear to break-in and loosens up the denim cloth.

15. Reverse Denim

    A novelty use of denim-turned inside out to give jeans a really different look.

16. Ring Denim

    A traditional type of denim fabric, revived in the late ’80s and early ’90-s, using the ring-spun yarn for the warp. Characterized by a softer hand and an uneven surface appearance.

17. Ring-Ring Denim

    Ring/Ring or double ring-spun denim uses the ring-spun yarn for both warp and weft. This is the traditional way to produce denim. It’s possible to combine a ring-spun warp fabric with an Open End Weft, to get much of the strength and look of the traditional ring/ring denim at a lower cost.

18. Ring-spun Denim

    Ringspun yarns were traditionally used in denim up until the late 1970s but were later supplanted by cheaper Open End yarns. This is a spinning process in which the individual fibres are fed onto the end of the yarn while it is in the “twisting” stage. The process consists of a ring, a ring traveller and a bobbin that rotates at high speed. The ring-spun yarn produced by this method creates unique surface characteristics in the fabric, including unevenness, which gives jeans an irregular authentic vintage look. Ring-spun yarns add strength, softness, and character to denim fabric.

Denim Washing

Dramatic changes have occurred in the function and design of jean garments since the first pairs of jeans were created for gold miners during the California Gold Rush. The evolution of the jeans’ market led to the development of some unique and creative methods for the processing of denim garments. Originally, jeans were marketed and sold as workwear with primary emphasis on their durability and practicality.

But when jeans were discovered and appreciated by consumers as general casual wear, they became fashionable, and new techniques were developed to enhance denim garments and make them more unique. These techniques include garment washing, stone washing, stone washing with chlorine, ice washing, and cellulase enzyme washing. Basically, all of these techniques involve the processing of garments in rotary drum machines.

The first generation of indigo jeans was stiff and uncomfortable when first purchased, due to the finishing techniques used for denim fabrics. Normally after weaving, greige denim is singed, finished with starch and a lubricant, and then mechanically shrunk. This mechanical shrinking did “break” the hand somewhat, but no other processing techniques were employed to provide a soft handle.

Usually, consumers would take a newly purchased pair of jeans home and soften them by washing once or several times before the first wearing. Denim fabric continues to be processed using the same basic finishing system, but after being cut and sewn, denim garments may undergo additional processing.

The second generation of the jeans’ market evolution produced pre-washed jeans by the manufacturer. These jeans had a slightly faded appearance and a softer hand that felt comfortable, as though they had been laundered several times. This trend became fashionable as well, and consumers were willing to pay the extra cost involved in this additional processing. Consumers no longer had to bother “breaking-in” their jeans themselves with the added benefit that the jeans were already shrunk to size with little or no residual shrinkage.

Not long after the introduction of pre-washed jeans, the idea of using abrasive stones to accelerate the ageing process was developed and “stone washing” was born, creating an even more “broken-in” look. Next, chlorine bleach was incorporated in these wash techniques and a whole new paler blue denim family evolved. Then, ice washing was developed, in which the porous stones are soaked in a bleaching agent and then tumbled with dry or slightly damp garments. This process has been given many names, including acid wash, snow wash, whitewash, frosted, etc. Actually, the term “acid wash” is a misnomer since acids alone should never be used for this process.

Most recently, a cellulase wash procedure was developed in which cellulase enzymes were used to accelerate colour and fibre removal. A reduced quantity of stones can be used to create a desirable washed down appearance. This process can be more efficient; since with fewer stones, larger load sizes can be processed, and there is less of an abrasive effect on the inside of the rotary drum.

Famous Denim Terms

• Stonewashing: A process that physically removes colour and adds contrast. Jeans and stones are rotated together for a set period of time. The washing time dictates the final colour of the fabric – the longer the denim and stones are rotated the lighter the colour becomes and more contrast is achieved. The denim is then rinsed, softened and tumble dried.
• River Washing: A washing process using a combination of pumice stones and cellulose enzymes to give denim a vintage, worn hand. The washer is loaded only with stones and fabric for the first cycle. Enzymes are introduced for the second stage in combination with the stones and they are tumbled until a naturally aged look is produced.
• Indigo: The dye used for denim, initially taken from the Indigofera tinctoria plant. The majority of indigo used today is synthetically made. Natural indigo has a slight red cast.
• Tate-Ochi: Japanese term referring to occurrences of ‘Iron-Ochi’ forming in vertical lines in vintage denim. As the thread width is not uniform in vintage denim, the colour fades the most where the thread is the thickest. This creates a white or severely faded thread of several centimetres along a single vertical indigo thread.