What To Really Know Before Buying Your Next Pair Of Jeans

When it comes to your favorite pair of jeans, there’s far more than meets the eye. Sure, you already know your preferred washes and silhouettes, but what you’re probably not aware of are the crazy technicalities that go into manufacturing your trusted denim pants. Well, we’re about to change the way you see your beloved blues.

Get a glimpse into the specialized world of denim-making. From A to Z, read up on the nerdiest technical denim terms you need to know and love: learn about the tiniest details, the masterful craftsmanship of hand sandpapering, the science behind stretch fabric, the intricate ways yarn is spun, and more. And to get you primed on all your future denim-inspecting, we’ve also paired a jean to match each alphabet letter for a complete denim glossary. This is vocabulary you’ll be glad to get schooled on before your next purchase.
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Just like the term implies, abrasion is the process of making jeans look and feel worn and aged by scraping or rubbing the fabric surface using sandpaper or pumice stones. You can see how abrasion was used in these Siwy skinnies to create areas of distress.

Acid Wash
Acid Wash — also known as marble, moon, or snow wash — is a wash process that uses sponges or pumice stones soaked in chlorine to give a high-contrast, '80s punk rock look.

Alchemy One
Coined by 7 For All Mankind, this term is the name of the brand’s new eco-friendly fabric that’s made with virtually no water, and the chemicals that are used get constantly recycled. California denim brands, take note.

The arcuate is that unmistakeable V-shaped stitched pattern on the butt pockets of Levi’s.
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A term most denim lovers already know, bleaching involves stripping denim of its impurities — for example, uneven patches of color in the fabric — to create that faded look. You can see how these 7 For All Mankind rolled-up skinnies have bleached, white splotches against the light blue denim.

Tiny bits of thick hand- or machine-made stitches used as reinforcements in areas like pocket openings, fly openings, or buttonholes.

Bias Tape
A bias tape is a narrow strip of fabric that is cut against the grain, making it more flexible to apply to curved lines; it's used along pockets and hems as reinforcement.

Bodycon Denim
“Bodycon Denim,” a term specific to MiH, is the brand’s line of revolutionary bounce-back denim that with a tight, bodycon fit. MiH uses fabric technology where the yarn is spun in a coil, so it acts like a spring and ensures the jeans won't lose their shape.

Broken Twill
Look closely at your jeans and you’ll see certain weave shapes. The broken twill gives a “w” look to the fabric, often in a distinctive bright blue shade. It was first used by Wrangler on 1970s bell-bottoms and classic denim jackets.

Bull Denim
A type of heavyweight woven fabric called 3x1, which means 3 weft threads per 1 warp thread (more on these terms later), which is usually dyed after making the jeans.
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Caste is the name of the different kinds of indigo shading on your jeans, which explains why certain types of denim tend to have those green, red, yellow, or brown undertones. These 3x1 skinny jeans have a red caste to them.

You guessed it — it’s a type of stitching that looks like a chain, which is an ideal mix of flexibility and strength.

This lightweight plain weave cotton is a great alternative to thick denim in the summer. It’s made with a single-colored warp and white weft, which gives it that light blue color.

Comfort Stretch
This type of denim has less than 1%-35% elasticity and is often used in men’s denim and for women’s boyfriend jeans, flares, and straight legs — in essence, for styles that have slightly looser fits.

To fit the woman’s figure, denim is cut to contour at the hips and side seams and narrow at the waist to help prevent against gapping in the back.

Core Spun
The core spun process is when the core of the fiber is elastic and the cotton is spun around it to give it a soft hand.

Crocking is the annoying thing that happens when the indigo dye from a pair of jeans rubs off on another surface like your skin, the chair you sit on, or your clothing. It’s what happens when a lot of indigo sits on the surface of the denim and is prone to rubbing off.

Crosshatch is a type of weave where yarns intersect to make a cross on the surface.
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Dry Process
The dry process is what is done to jeans by hand before they go into the wash — literally, the dry stage. AYR’s dry process involves hand-destroying jeans using tools like Dremels and sandpaper. After that, the pair is thrown into machines which help loosen up the holes. A pair like the one you see here would have gone through both a dry and wet process to achieve its final look.

Double Needle
This type of stitching uses two needles to create parallel seams, which strengthens the garment and provides a finished look.

Dual Flex Fabric
This type of fabric uses yarn at the core made from polyester (for strength) and cotton on the outside (for softness and to hold the dye).
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Elasticity Vs. Content
Let’s break this down: Content describes the percentages of fiber in the denim, and elasticity describes how much the denim stretches beyond its resting form. A bunch of factors determine the elasticity: the way it’s woven, finished, and how it’s treated during the wash process. This patchwork pair from Paige may not have a ton of elasticity, but its finish makes this boyfriend jean feel super soft.

Coined by the brand Hudson, this luxe denim fabric is handcrafted from viscose-rich yarns and redefines stretch and recovery. The viscose yarns makes the fabric super soft, but that doesn’t mean the jeans will get baggy — these jeans have a 45% stretch and a 92% recovery, which means they'll snap back into their original form after a day of wear.

Enzyme Wash
Oh yes, we’re going back to biology class. If you need a refresher, enzymes are proteins that act as catalysts to increase the speed of chemical processes. In an enzyme wash, which is an eco-friendly alternative to the stonewash, enzymes are used to help eat away at the indigo dye, rather than using pumice stones to beat away at the fabric.
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Five Pocket Jeans
It’s your standard jean with five functional pockets: two in the back, two in the front, and a small coin pocket inside the right front pocket. Even the most modern denim updates, like these culottes from KUT from the Kloth, have all five pockets accounted for.

Also known as weft yarn, fill yarn runs crosswise, which explains why some jeans have thin, horizontal stripes running across them.

The finishing relates to all the techniques and processes that are performed on jeans to give them a finished look. For example, a pair of jeans could be thrown into a finishing wash to set the fray on a rip, or any embellishments could be added if a style of jeans called for decorative studs.

Flat Felt Seam
Similar to the double needle stitch, flat felt seams use two needles for the inseam of a jean, which makes it strong and durable. Take a look at the seams of your jeans — the parallel stitch lines are called a flat felt seam.
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Garment Dye
There two types of dye processes that happen when making a pair of jeans: one is when a garment is dyed at the very end (garment dye), and the other is when the dying takes place prior to the weaving of the yarn (yarn dye). This Mavi pair in rich indigo with dark knee patches is an example of jeans that went through the garment dye process.

Another form of surface abrasion, grinding is applied to the pocket edges and bottom hem to create that frayed, worn-out effect.
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You know that grid of whiskers that forms behind the knees on your jeans? It’s called a honeycomb, named for the shape it makes. These AG jeans feature honeycombs at backs of the knees.

Hand Sanding
Hand sanding, which falls under dry process and abrasion, is how brands get their styles to look super worn-in and vintage without the aging process.

Hemp Denim
This one’s very literal: It’s denim made using the hemp fiber.
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Indigo, the one dye we cannot stop talking about, dates back to ancient times when it was organically extracted from plants for cotton weaves (which is how the “blue” jean got its distinctive color). Nowadays, many indigos are synthetically created — like these Industry Standard skinnies, which feature a beautifully deep indigo hue.
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Jet Pockets
Check out the front pockets on these MiH flares and you’ll notice the ‘70s jet pockets (also known as welt pockets) — narrow rectangular pockets that are an alternative to curved front pockets.

This one is as literal as it sounds: It’s the J-shaped stitching that you find on the fly.
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Knee Bursts
These adorable, star-like lines that appear at the knees are called knee bursts, as seen on these Hudson bootcuts.

Kick Flare
Named after the classic 1970s jean, kick flares are tight at the thighs then rapidly flare out, starting right above the knee and down to the ground, to cover platform shoes.
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Laser Whiskers
Since hand-sanding tends to be so labor-intensive, lasers are often used create the same abrasion and grinding effects since it’s faster, more precise, cheaper, and oftentimes, more eco-friendly. Check out the lasered-on whiskers of these Ksubi destroyed jeans.

Loomstate is the fabric that comes straight off a loom, which means there’s no sanforizing, anti-skewing, singeing, or other finishing processes applied. This fabric is as natural as it gets.

Lyocell is a generic term for tencel, a sustainable fabric that is regenerated from wood cellulose.
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Mercerization is the heat and pressure process that adds shine to natural fiber fabrics, which is why certain jeans appear to have a silvery sheen to them, such as these Blank NYC blues.

Monkey Bleach
Monkey bleach is defined as a placement bleach that adds a vintage look to jeans.
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Natural Fibers
As you can probably guess, natural fibers are fibers that come straight and unfettered from the earth. The most important and widespread fiber is cotton. These Genetic cropped high-waisted jeans are made of 98% organic cotton (the other 2% is elastane).
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Original Hem
Also referred to as a “tricky” hem, the original hem is the term to know if you’re going to shorten a pair of jeans. Ask the tailor to re-attach the jean’s original hem to give your altered jeans that same, authentic look. You don’t want to mess with a hem like these perfectly frayed Current/Elliott jeans.

This is a natural process where chemical reactions change the surface characteristics of jeans due to materials being exposed to oxygen.

Ozone Wash
This revolutionary wash method uses no water (essential for those Cali-based denim brands facing the drought epidemic) and achieves a yellowed/faded effect on the denim for a vintage look. The garments are rinsed afterwards to get rid of the smell from the ozone wash.
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Power Stretch
Power stretch is the term that is applied to fabrics with superior bounce-back recovery so silhouettes don’t lose too much shape after a ton of wear. Depending on the color, these power stretch skinnies from Uniqlo feature anywhere from 88%-93% cotton, 5-8% polyester, and 2-4% spandex for ultimate jegging-like movement but with the recovery of denim.

Short for the term “prepared for dye,” this is used to prevent the dye from being fully absorbed into the fibers.

Patching & Repair
This DIY-like process is about creating intricately destroyed and patched denim using contrast patches on the reverse (inside) of destroyed jeans with a series of complex re-sewing processes.

Pigment Dye
This is a dying process where dye sticks to the fabric, but no chemical reaction takes place between the dye and the fabric.

Potassium Spray
Another way to make jeans look distressed is to use potassium spray, which turns certain areas of the garment white. This process can be done either during a hand scrape or in the middle of the wash.

Pumice Stones
These are the stones used in “stone” washes.
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Okay, so quick-dry isn’t a true “technical” term, but the new Levi’s Commuter denim collection has gone next-level with water-resistant technology. The surface tension is reduced because paraffin chains (a water-resisting product) are wrapped around every fiber in the denim — water droplets just run off. And any moisture that does get trapped simply wicks away quickly.
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You’ve read a lot about recovery by now — how well a pair of jeans goes back to its original shape after they've been stretched. Citizens of Humanity has just launched a collection of skinny and flared jeans in a brand-new SCULPT fabric that has the brand’s best stretch and recovery yet, using a unique Lycra weaving technique. The brand guarantees these cosmic skinnies won’t get baggy at the knees.

Resin is the tree sap that you’re already familiar with, but in denim-making, it is used to hold the color or the shape of 3D-manipulated denim.

This is denim fabric that hasn’t been washed at an industrial denim laundry — it’s stiff and tough denim for wearers who love really break in their jeans over many years.

Look closely and you’ll see that many types of denim weave run diagonally. If the weave goes up and towards the right, it’s a right-hand.

These are small metal accessories that are used to reinforce stress points and serve as non-functional ornamentation.
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Selvage (or Selvedge)
Selvage is a self-finished edge of fabric, or a tightly woven band that is attached to the unfinished edges of denim to prevent the fabric from unravelling. These are generally thought of as "high-end,” since you can only create a few pairs from each roll of selvage fabric, like this pair from Rag & Bone.

This fancy term refers to the pre-shrinking fabric process, which limits the shrinkage of your denim — a big plus so you don’t end up with tiny pants after the first wash.

Shank Button
That main button you see used for the closure of jeans is a two-piece button that is attached with metal shank.

If you’ve ever found denim to have uneven texture, that’s what the industry calls a slub.

Staple Fibers
Staple fibers relate to the length. Longer fibers tend to have a smoother finish.

Ah, the stonewash. This is the treatment where pumice stones are added to the wash cycle with the denim in order to lighten up jeans.

SPI is short for “space per inch” and it relates to the measurements in-between each stitch. Depending on the SPI and thread weight, it can make the back pocket profile slimmer and more refined on a pair of jeans.

Super Stretch
Isn’t it incredible how much stretch is pivotal in the creation of jeans? Denim that has 35% or more elasticity is considered super stretch denim and is used for the skinniest of fits (and also flares and straight leg silhouettes).
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Tencel (also known as Lyocell, previously mentioned in the L category) is a sustainable, man-made fabric regenerated from bleached wood pulp. These days, Tencel is incorporated into many jeans because it's soft, absorbent, and resistant to wrinkles. This pair from DSTLD is made with 42% Tencel to give it that lightweight and breathable quality.

This is the process of adding a little bit of color to give a pair of jeans a slightly different shade.

Twill is the name for diagonal lines formed by the weave (you’ll see this if you look closely at your thicker denim jeans).
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Unwashed jeans — which have skipped the laundry process — are known for their raw and stiff fabric that are fun to break into, if you’ve got the time. The unwashed, raw form is a style signature of French denim brand A.P.C..

This eco-friendly process involves converting waste or scrap materials into newer, usable materials. It’s a win-win, because upcycling usually produces better-quality products with environmental value.
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While “vintage” is not a technical term, it’s a word that makes our ears perk when we talk about denim. If you’re into the heritage of Levi’s, look no further than the high-rises of Re/Done jeans which are repaired and restructured to fit the modern-day body.
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Warp & Weft
You’ll see that the terms warp and weft are often cited together — warp are vertical yarns that are woven into the weft (horizontal) yarns, and weft are horizontal yarns that are woven into warp (vertical) yarns. Generally, though, warp tend to have more twist and are stronger than weft. Thinner-fabric denim in a skinnier fit tends to have grid-like woven patterns that run up and down and side to side — look closely at these cropped Baldwin jeans to see those perpendicular lines.

The weight of denim (mostly measured in ounces) denotes how dense and heavy the denim is: the higher the weight, the thicker the denim; the lighter the weight, the thinner the denim.

The fading of the ridges in creases around the crotch area and the back of the knees are affectionately known as whiskers. Though too much manufactured whiskering can call attention to a wearer’s crotch in an unappealing way (yes, we went there), these lines are used to give the appearance of aged denim.
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X-Tra Long Inseams
While there isn’t a true technical term for extra-long inseams, the mechanics of creating jeans proportionate for taller girls are worth a mention. For example, these 40” inseam Karlie Forever flares from Frame feature a high knee break, a higher rise (to fit the longer torso), and billow out to skim the ground (to cover a platform shoe).

The XX, which is a term specific to the Levi’s legacy, is the name of the denim used for Levi’s Riveted Overalls in 1873 and continued into the brand’s 501 styles. In 1983, Cone Mills introduced XXX denim on wide looms.
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Flip jeans around to the backside and you’ll see the yoke — the triangular, V-shaped seam below the waistband that gives curve and shape to the butt area. Depending on how straight or short the yoke is determines how the jeans will fit your derriere. These ankle jeans from Joe’s feature a great curve that is modest and still sexy.

Yarn Dye
Some fabrics are created by dying individual yarns prior to weaving, and denim is one of them. It is woven from yarns that are the color of the finished fabric: blue, traditionally.
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The Z-twist literally refers to the Z-shape direction of how the denim yarn is spun — in a clockwise direction, so that if you see it from any angle, the fibers angle slightly to the right. Most denim yarns are Z-twist, which you can see upon careful inspection on these Big Star boyfriend crops.

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