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Answers to all your questions about denim and how it’s made.

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How Denim Is Made

Looking for more details? In the sections below, we explain the five stages of making denim, step by step. Scroll through the page or jump to a specific section:

Raw Materials

Cotton – a natural fibre from the fruit of the cotton plant

How cotton is made – it takes an average of 140 days from planting to picking

Staple length – staple length refers to the length of the fibre

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Spinning explained – spinning is the process of turning fibres into yarn

How yarn is spun – there are two stages in the spinning process: preparation and the actual spinning

Yarn count – yarn count describes the thickness of yarn

Slubs – slubs are thickenings in yarn that result in a desired unevenness in the colours of denim

Ring spinning – ring spinning is the old-school way that create more slubs in the yarn

Open-end spinning – open-end spinning creates a more even and flat denim. The cotton is fed directly into the ‘spinner’ by a stream of air

The history of spinning – before the Industrial Revolution, spinning was a manual operation

Stretch denim – denim that contains a synthetic elastomer in the yarn (usually only the weft)

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Dyeing explained – dyeing is the process of adding colour to yarn

Indigo explained – indigo is the colour that makes blue jeans blue

How to dye with indigo – to get the indigo onto the yarn or the fabric, it’s solubilised in water with the help of a reducing agent

Natural indigo – indigo pigments that are extracted from dried leaves from the indigofera tinctoria plant

Synthetic indigo – a synthesised version of indigo, which is used for almost all denim today

The history of indigo – archaeologists have traced the use of indigo back 6,000 years

Rope dyeing – a continuous dyeing method where the yarns are roped together during the process

Slasher dyeing – a continuous dyeing method where the yarns are laid out as a carpet, also called a sheet, during the process

Hank dyeing – a dyeing method where bundles of yarn, known as ‘skeins,’ are dyed by hand

Rope dyeing and slasher dyeing compared

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Weaving – the process of interlacing of two sets of yarn

Selvedge denim – denim woven on shuttle looms, which is recognised by the self-finished edges of the fabric

Warp and weft – are the names of the two yarns used to weave denim

Right hand, left hand, and broken twill – different types of twill weaves

Shuttle loom – is the type of loom used to weave selvedge denim

Shuttle – is a device used to carry the weft yarn back and forth on a shuttle loom

Wide loom (shuttleless loom) – is the modern type of weaving machine that most denim is made on today

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Fabric finishing

Fabric finishing – processes that either correct and prevent issues of dimensional stability or enhance the look and feel of the denim

Loomstate denim – is denim that hasn’t been treated with any fabric finishing

Sanforization – is a finish of pre-shrinking fabric before it is made into a garment

Pre-skewing – is a finish that eliminates leg twist

Mercerisation – a finish that opens the fibres and gives them a rounder shape

Singeing – is a finish that makes denim smoother

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