Maybe you have wondered what words like selvedge or back yoke mean when reading about jeans?
The list of technical terms is long, and mastering every item on it is a bit of a mouthful. That’s why we’ve put together this denim dictionary and a list of the nine most essential jeans anatomy terms. Knowing what they mean will not only make it easier for you to find the perfect fit and style, you will probably also appreciate your jeans even more.
We start with the nine most essentials features of jeans.
The fundamental design of jeans has remained unchanged for almost 150 years. The one key detail that differentiates jeans from other pants is the rivets that you find at the stress points of pocket corners. Today, rivets are mainly there because they look good, but when they first made their way onto the pocket corners they served a vital purpose by extending the lifetime of the pants.
One of the unique construction features of jeans is the yoke: the V-shaped top on the back. The yoke is what gives jeans their figure hugging fit.
The coin pocket is the small pocket that is half-way tucked inside the left front pocket. It is often mistaken for the fifth pocket in “five-pocket” jeans, but in fact the left back pocket was the last to be added to the generic jean.
Until the early 20th century, people mostly relied on braces to keep up their trousers. However, as wearers started preferring belts, the five loops were added to the waistband as a way to keep the belt in place, and the cinch and suspender buttons were scrapped. Jeans commonly feature five belt loops.
Denim is the foundation of jeanswear. The hard-wearing twill fabric has been a favourite among workers for centuries, but it slowly became part of the fashion scene during the 20th century. Denim is usually made of cotton, but today synthetic fibres are often added to increase flexibility. The word “denim” is commonly believed to derive from “serge de Nîmes;” a fabric that originated from the French town Nîmes.
Warp and Weft
Like other twill fabrics, denim consists of warp and weft yarns. The way the warp and weft yarns are combined is referred to as the weave, and it affects the appearance, feel, and durability of the fabric. The warp runs along the length of the fabric and the weft runs across it; on the front there are usually three warp yarns per each weft yarn, which is known as a 3/1 twill. Traditionally, only the warp is dyed with indigo, which is why denim is blue on one side and white on the other.
Selvedge denim is woven the traditional way on narrow shuttle looms. The name refers to the weave, which has one continuous cross-thread (the weft) that is shuttled back and forth. This creates the tight “self-edge.” Because it’s produced at slow speed, selvedge denim is soft and durable. JACK & JONES primarily uses Japanese and Italian selvedge denims that are known for their quality and craftsmanship.
You may have come across the abbreviation oz when reading about denim. It’s got nothing to do with fantasy films or prison TV shows, but refers to the weight (in ounces) of the denim per square yard.
Now, if you want to study the anatomy of jeans in even greater detail, below is our entire denim dictionary.
JACK & JONES Denim Dictionary
3/1 weave Refers to the number of weft threads per warp thread. Traditional denim is woven in a 3/1 weave.
3D effect An effect where resin is sprayed onto the jeans while they are on a mannequin. The jeans go through a 3D shaping in order to make the folds at the hips, knees and bottoms of the legs look natural.
Ab rasion The surface of the fabric is scraped or rubbed to make it look and feel worn and aged.
Back cinch A buckle on the back of the jeans which was used to tighten the waist before belts became common.
Back yoke One of the unique construction features of jeans is the yoke: the V-shaped top on the back. The yoke is what gives jeans their figure hugging fit.
Baking process Once resin has been applied to the jeans and they have been shaped on mannequins, they are put into a large industrial oven to harden the effect.
Bartack Handmade or machine made stitches that reinforce points of strain, usually found at the top corners of the back pockets, the base of the fly and buttonholes and belt loops.
Belt loop Loops around the waist that hold a belt. In the 1920s the belt loops were introduced to slowly replace suspender buttons. Most jeans have five belt loops.
Breaks and repairs Describes the different wash and treatment technologies we use to recreate authentically worn in denim garments. Most breaks and repairs are handmade by skilled craftsmen, and no two items are identical. However, advancements in treatment technologies now enabled us simplify certain steps of the process to ensure a high level of quality consistency.
Broken twill Broken twill was invented to prevent leg twist and the characteristic zig-zag weave is created as the direction of the weft shifts with every third pick.
Brush A rotating tool is used to create a naturally soft and even look on the thighs and back.
Button fly The traditional fly with buttons instead of a zip.
Buttons Functional buttons with buttonholes first appeared in Germany in the 13th century. Up until this point buttons served a decorative purpose.
Carding The process of removing foreign matter from cotton fibres with large brushes. At the same time the cotton is detangled and straightened. The cleaned cotton strings are called slivers.
Cast The shading or tone on denim. Indigo denim can have a black, brown, grey, green, red, or yellow cast.
Chain stitching One continuously looping thread that forms a chain-like pattern, used to hem jeans. Also used at the waistband.
Coating The woven denim is coated with a starchy substance to give it a certain colour or shiny surface.
Coin pocket The coin pocket is the small pocket that is half-way tucked inside the left front pocket. It is often mistaken for the fifth pocket in “five-pocket” jeans, but in fact the left back pocket was the last to be added to the generic jean. The fifth pocket is the second (left) back pocket, which was introduced in 1901.
Cotton gin Invented and patented by Eli Whitney in 1794, this machine revolutionized the cotton industry. The cotton gin removes the cotton fibres from the seeds by means of wire hooks in a cylinder, thereby making the process fifty times faster than doing it by hand.
Cutting the fabric The process of cutting out graded pattern pieces that will later be sewn into jeans. The fabric is stacked in layers of up to 80 pieces.
Denim A sturdy cotton fabric which can be traced back to the 1500s, where it was worn by Genoese sailors. This also explains where the word ‘jeans’ has its roots. The denim cotton originated in the French town of Nîmes, hence the name ‘denim’.
Dips The process of plunging yarn into indigo dye. It also refers to the amount of times the yarn has been dipped – the larger the amount, the darker the shade.
Dirt effect The dirt effect is hand painted or sprayed onto the jeans.
Double needle stitch Also referred to as a twin needle, the double needle stitching method makes two parallel rows of stitches which provide strength.
Drill A fabric with a strong, diagonal twill weave.
Dry denim The same as raw denim; it refers to jeans that are unwashed.
Dyeing Thick slivers of yarn are dipped in vats of indigo dye before the yarn is woven. There are two predominant ways of dyeing the yarn – rope dyeing and slasher dyeing. Rope dyeing is when the yarns form a ‘rope’ and are then dipped in indigo. Slasher dyeing is when individual yarns are dipped in dye.
Ecru The natural colour of cotton which has not been dyed.
Elastane A synthetic fibre known for its remarkable elasticity.
Enzyme Wash An eco-friendly alternative to stone wash. An enzyme wash uses organic enzymes which attack the indigo and lighten the colour of the denim.
Fabric mill A place where the cotton is processed and eventually woven into fabric.
Fibre A type of hair-like threads that constitute fabrics and are divided into two categories: natural and synthetic.
Flat finish A process done at the fabric mill to give the denim an evenly distributed wash-down colour and smooth surface.
Fly Either a zipped or buttoned opening in front of the jeans. Different versions of the fly have been used since the 16th century.
Ginning The process of removing the seeds from the cotton.
Grinding A surface abrasion applied to the pocket edges and the bottom hem edges. This creates a wornout effect.
Hand scraping A manual treatment where sandpaper is used to give the jeans a worn look.
Honeycombs This effect is made with sandpaper on the area behind the knees which fades during the wear process. The fading looks like actual honeycombs.
Ice Blast Ice Blast is a new JACK & JONES treatment where liquid CO2 is turned into dry ice and used to recreate naturally worn in denim looks. The dry ice is blasted onto the denim to fade it at a chilling -78°C. The results resemble those achieved with traditional fading agents, but since the dry ice is basically water it dissolves naturally. This means that no water is needed to rinse the garments, and the total amount of water required in the wash cycle is drastically reduced. And since the CO2 used to make the dry ice is recovered from other production steps, no new energy is required to produce it.
Inch 2.54 centimeters.
Indigo dye The technical reason for indigo dyed denim’s ability to fade is fairly simple. Unlike most other dyestuffs, the indigo dye doesn’t penetrate to the core of the yarn. When the denim is worn and gets abraded, the indigo slowly rubs off and the white core gradually becomes visible.
Indigo Knit Indigo Knit fuses the best of two worlds. It combines the superb comfort of knitted sweatwear with the authentic indigo look of denim. Like denim garments, our Indigo Knit selection is treated with both wet and dry processes such as 3D shaping, breaks and repairs, and different fading agents to get the naturally worn in look. Although Indigo Knit is in fact technically a woven fabric, it feels more like knitted sweatwear than denim. Cotton fibres are carted, spun, indigo dyed, and finally woven. Polyester and elastane are added to the cotton to increase flexibility and fabric recovery.
Indigofera plant (True indigo) The flowering plant from which the indigo pigment was extracted until artificial indigo dye was introduced.
Inseam Refers to the length of the inside of the leg, measured from the crotch to the leg opening.
JACK & JONES signature stitch Two stylised Js embroidered on the back pockets.
Laser A laser creates the same effects as those achieved with hand scraping, except they are faster, more even and much more precise. It’s also used in ecofriendly treatments such as Low Impact Denim.
Laundry Denim in its raw state is sent to laundries – factories where the denim is put through different processes to finalize the look.
Left hand twill A method of weaving where the weave runs from the top left corner of the fabric towards the bottom right corner. Left hand twill usually has a soft hand feel and fades a little differently compared to right hand twill.
Leg opening A term used to describe the circumference of the opening of the leg of jeans and pants.
Loom A machine used to weave the fabric. It works by intertwining the long, warp yarns with the crosswise weft yarns.
Low Impact Denim Low Impact Denim is a certified JACK & JONES initiative that makes our jeans more eco-friendly by lowering the environmental impact of their production. By using cutting edge technologies, we to reduce the amount of water and energy consumed when finishing our jeans and we minimise the amount of waste produced. The jeans look and feel just like they would with conventional finishing procedures, but water consumption is reduced by a minimum of 40% while energy consumption is down by at least 30% compared to our average benchmark. When possible, leftover material is recycled to produce new denim fabrics.
Marble wash Also known as acid wash. It’s a treatment where pumice stones are soaked in a bleaching agent and then added to the wash cycle along with the jeans. It creates a sharp colour contrast on the finished jeans.
Moustache/whiskers One of the most commonly used effects around the thigh area. It can be made with both sandpaper and laser, and is used to recreate the characteristic worn in look. The wear pattern often looks like the whiskers of a cat, but it is also referred to as moustache.
Open end denim Less expensive than ring-spun denim, open end denim “mock twists” the fibres by pressing them into shape.
Ounce (oz) A unit of weight used for denim. 1 ounce equals 28.35 grams. It indicates the weight of one square metre of denim. Light denim might be more expensive to produce than heavier denim because of the finer yarns used.
Ozone An environmentally friendly lightening process which doesn’t use any water in the wash cycle.
Pattern design Process of making the pattern for a pair of jeans, based on the designer’s sketches. A traditional 5-pocket jean consists of around 20 individual pieces.
Ply Refers to the number of threads twisted together in a yarn.
Pocket bags The pocket bags are the fabric (often a twill) used to make the front pockets of jeans.
PP spray A mix of fading agents sprayed onto the jeans to accentuate the bright areas created by hand scraping. The spray is pink or purple when sprayed on so the workers can see the already sprayed areas. After a neutralising wash cycle that washes out the colour, the effect becomes visible.
Pressing The jeans are ironed and finished at a pressing house before being packed. Some jeans are not ironed to maintain the worn look.
Production line The jeans are sewn by specialized seamstresses in a sequential order, where each pair ends up being sewn in the exact same way.
Prototype An early sample of the jeans that is made to test a concept. This makes it easier for the designer and pattern maker to make adjustments before sending the final version through to sales samples and then to production.
Quality control The jeans go through a series of quality controls throughout every process, starting from the raw material itself to the final product.
Random wash Small towels that have been soaked in a bleaching agent are put into the washing machine together with the jeans. This creates a random bleached look.
Raw denim Denim that has not undergone any washing or treatment processes.
Resin A solution used on jeans for several purposes: prepare them for 3D shaping, make the garments absorb treatments and also add shine to the denim.
Right hand twill A method of weaving where the weave runs from the top right-hand corner of the fabric towards the bottom left-hand corner. The right hand twill is the most common weaving method for denim.
Ring spun Created by continuously rolling and thinning fibres into shape. It makes the yarn more uniform and stronger.
Rinse wash A process where the jeans are only rinsed and not put through an actual wash cycle. The rinse softens the fabric.
Rivet A small, mechanical fastener used to provide reinforcement in places prone to rip, such as pockets corners.
Rubber ball treatment Rubber balls are added into the washing machine to break up the starch and make the jeans softer without using water.
Sanforization A treatment that stabilizes the fabric before it is cut and keeps it from shrinking after it has been washed.
Scraping A treatment where the jeans are scraped with sandpaper to get a worn look. It can either be done manually or mechanically, depending on the wanted degree of wear.
Seam The line where the layers of the fabric are sewn together. In clothing, seams are categorized by their type (plain, lapped etc.) and placement (inseam, side seam, etc.).
Selvedge denim Selvedge denim is woven the traditional way on narrow shuttle looms. The name refers to the weave, which has one continuous cross-thread (the weft) that is shuttled back and forth. This creates the tight “self-edge.” Because it’s produced at slow speed, selvedge denim is soft and durable. JACK & JONE S primarily uses Japanese and Italian selvedge denims that are known for their quality and craftsmanship.
Spinning The process of pulling and twisting the fibres to strengthen them and turn them into yarn.
Sponge effect Bleach is applied to the jeans with a sponge. This creates a different look than bleach which is sprayed on.
Stonewash A laundry treatment where pumice stones are added to the wash cycle with the denim in order to abrade and lighten the jeans.
Super stonewash The regular stonewash is amplified by adding bigger stones for a longer time in the wash cycle. It creates a very light and worn look.
Super Stretch Super Stretch is a new extremely flexible JACK & JONES denim that never gets saggy. It contains an innovative fibre mix; elastane makes the denim stretch to extreme dimensions while polyester ensures that your jeans keep their shape. With Super Stretch denim you will experience incredible comfort in a real pair of jeans.
Tagging Fabric is folded and afterwards fixed with swift tags. When the tags are removed, they leave a dark area inside the fold, replicating a natural fold which comes after wearing a pair of jeans for months.
Thread The classic tobacco coloured thread is commonly used for stitching jeans. There is a variety of colours, depending on the desired style and effect. 240 metres of thread are used for a pair of 5 pocket jeans.
Triple needle stitch Workwear inspired stitching detail which signals durability and authenticity.
Twill A specific type of weave. It is a pattern of diagonally woven ribs, where the weft thread is passed under and over one or more warp threads.
Unwashed Another term for raw denim. The jeans have not been washed and are stiff, giving the wearer the opportunity to break them in and make them adapt to his body.
Waist The length of a waistband on a pair of jeans indicates their size, measured in inches.
Waistband The top part of a pair of jeans. The waistband is equipped with belt loops, labels and a button.
Warp and weft Like other twill fabrics, denim consists of warp and weft yarns. The way the warp and weft yarns are combined is referred to as the weave, and it affects the appearance, feel, and durability of the fabric. The warp runs along the length of the fabric and the weft runs across it; on the front there are usually three warp yarns per each weft yarn, which is known as a 3/1 twill. Traditionally, only the warp is dyed with indigo, which is why denim is blue on one side and white on the other.
Yarn count Refers to the fineness or thickness of a yarn. It is usually measured by the number of grams per one kilometre of yarn. This unit of measure is called “Tex”.
Zip fly The zip fly as we know it today was developed in the late 1920s.