Is Faux Denim Real Denim? Faux vs Real Denim, Explained

Is faux denim real denim? No, and that is the whole point of it. Real denim is a sturdy woven cotton cloth with a diagonal rib and a blue face. Faux denim is a different fabric, usually a stretchy knit, that is made to look like denim without being woven the way denim is. Think of it as a very convincing costume. From across the room it passes for jeans. Up close it behaves like leggings, because that is what it is. Neither one is better. They are built for different jobs, and this post explains the difference in plain English so you can pick the right one without feeling tricked.

We sell both, so we have no reason to pretend one is a fake version of the other. We have real denim jeans and we have faux denim leggings, and the honest answer to “which should I buy” is “what are you doing today?” We will get to that. First, let us find out what denim actually is, because most people (including most people who wear it daily) have never been told.

What is real denim, exactly?

Real denim is a cotton twill, and “twill” is just the name of a weave. To understand it, picture a woven basket. Woven fabric is made by crossing two sets of threads: the lengthwise ones, called the warp, and the crosswise ones, called the weft (sometimes the “filling”). In a plain weave the crosswise thread goes over one, under one, over one, under one. In a twill weave the crosswise thread goes over two or more lengthwise threads before it dips under, and it shifts over by one each row. That shift is what makes the diagonal ribbing you can see on the inside of your jeans.

Denim has one more trick. Wikipedia describes it as a sturdy, cotton, warp-faced textile, meaning the lengthwise threads are the ones you see on the front. In classic indigo denim the warp threads are dyed blue and the weft threads stay white. That is why a pair of jeans is blue on the outside and mostly pale on the inside. Britannica describes the same thing: a durable twill-woven fabric with colored (usually blue) warp and white filling threads, dyed as yarn before it is woven. So the next time someone tells you denim is “any blue pants fabric,” you can set them straight. Denim is a specific weave with a specific color setup.

One more detail, because it explains a lot later. Indigo dye mostly coats the outside of each yarn rather than soaking all the way through. As the jeans wear, the surface rubs off and the lighter inside of the thread peeks out. That is why denim fades, and why it fades most at the knees, seams and pockets, which are the places that get rubbed the most. A pair of jeans is basically a diary written in worn-out blue.

Where do the words “denim” and “jeans” come from?

Two different French places, believe it or not. “Denim” is said to come from the French phrase serge de Nîmes, meaning serge (a twill cloth) from the city of Nîmes. Shorten that over a few hundred years of people being lazy with words and you get “de Nîmes,” and then “denim.” Britannica is careful to say it is “said to” have originated there, and we are too.

“Jeans” has a different story. It comes from Gênes, the French word for Genoa, Italy. According to Wikipedia, a cloth called jean first appeared in Genoa in the 16th century, as a medium-quality, reasonably priced fustian (a sturdy cotton-blend cloth). So “denim” is the fabric from Nîmes and “jeans” is the cloth from Genoa. They became one thing in English because everybody kept mixing them up, which is also how most of English works.

So who invented jeans? (It is not who you think.)

Levi Strauss did not invent denim, and he did not invent jeans either. The famous moment is a patent. According to Wikipedia, a tailor named Jacob Davis wrote to Strauss in 1872 proposing a partnership, Strauss agreed, and in 1873 they received a US patent titled “Improvement in Fastening Pocket-Openings.” The big idea was putting metal rivets at the stress points of work pants so the pockets stopped ripping. Levi Strauss & Co. confirms the 1873 patent and the rivets on its own history page. Wikipedia gives the patent number as 139,121 and the date as May 20, 1873. We could only confirm that number and date from that one page, so take it as “Wikipedia says.”

The takeaway is that riveted work pants were the invention, and Davis shares the credit. Denim was already around. The rivets are what turned a tough cloth into the pair of jeans in your closet.

So what is faux denim?

“Faux” is French for fake, and it is a fair word here, as long as nobody takes it as an insult. Faux denim is a fabric made to look like denim without being woven denim. There is no official industry definition we could find, so here is our plain-English version: it is usually a stretchy knit fabric that has been colored, printed or washed to look like faded blue denim, and often finished with jeans-style details like stitching lines and a waistband tab.

The best-known cousin is the jegging, a word mashed together from “jeans” and “leggings.” Wikipedia describes jeggings as leggings styled to look like skin-tight jeans, and it separates them into two kinds:

• Knit jeggings are legging material, a knit, made to look like denim, sometimes with fake pockets and belt loops.
• Denim jeggings are made from real denim with extra spandex mixed in for legging-like stretch.

That is a useful distinction, because people argue about whether jeggings are “real.” The honest answer is that it depends which kind you bought.

Our faux denim leggings are the first kind. They are a knit, not a woven twill. The fabric is 86 percent nylon and 14 percent spandex, at 200 gsm (5.9 oz), and the look is a faded denim-style wash with a buckle tab at the waistband and stitching across the back. Nylon, if you are wondering, is another plastic fiber in the same general family of man-made fibers as polyester. Spandex is the stretchy one. If you want the gsm part explained like we are all ten years old, we wrote a whole post: What Is GSM in Fabric?

Woven vs knit, in plain English

This is the real difference, so it is worth slowing down for. Both are ways of turning thread into cloth.

• Woven fabric is threads crossing at right angles, like a basket or a woven mat. It tends to be flatter and firmer. Real denim is woven.
• Knit fabric is loops of thread hooked into other loops, like a sweater. It tends to be stretchy and soft. Most t-shirts and leggings are knits, and so is our faux denim.

Here is a way to remember it. Pull a loop in a sweater and it stretches and snaps back. Pull a thread in a basket and nothing much happens until it breaks. That is the difference in a nutshell. A knit moves with you. A woven holds its shape.

Real denim vs faux denim, side by side

Here is the comparison. The facts about real denim come from the sources linked below. The facts about our faux denim come from our own product page. Where a line is our reading rather than a measured fact, we say so.

How heavy is denim? (And where does faux land?)

Denim is usually talked about in ounces per square yard, the same measurement as in our GSM post. A denim publication called Heddels sorts denim into three weight classes: lightweight is under 12 oz, mid-weight is 12 to 16 oz, and heavyweight is 16 oz and up. Heddels also makes a point worth repeating: that is the weight of the fabric, not the finished jeans. A “14 oz” denim does not mean the pair of jeans weighs 14 ounces.

Converted with the same math we used in the GSM post (multiply ounces by 33.91), 12 oz is about 407 gsm and 16 oz is about 543 gsm. That puts the denim weight classes on the same ruler as everything else in this blog. Here is where some of our own pieces land:

That is the other big difference you will feel. A faux denim legging is light and soft because it is a thin knit. Real denim at 12 oz and up has real heft. We are not saying lighter is worse. A lightweight legging is exactly what you want for a long day of sitting, walking and not being squeezed. We are saying they are different animals.

Why real denim fades and faux denim does not

Remember the indigo coating the outside of the yarn? That is why real denim ages. As you wear it, the surface layer wears off and lighter yarn shows through, most at the knees, seams and pockets. Over months or years it builds a personal pattern of wear that nobody else has. Denim fans treat this like an art form.

A knit made to look like denim does not have that built-in aging system. Its faded look is part of how the fabric was made, not a layer waiting to wear away. That is our reading of how the pieces fit together, and we have not tested how our leggings age, so we are not going to make a promise either way. What we can say is that you should not expect knit faux denim to develop the same kind of wear pattern that a pair of woven jeans does. If a lived-in, one-of-a-kind fade matters to you, buy real denim. If you want the faded look from day one without waiting a few years, faux denim hands it to you.

What about stretch?

Classic denim does not stretch much. Stretch denim exists, though. Wikipedia says some denim yarns replace a few percent of the cotton with elastane (spandex or Lycra), up to about 3 percent, and that stretch denim can reach up to 15 percent elasticity. Our faux denim leggings have 14 percent spandex across the whole fabric, in a knit that is built to stretch anyway. So even “stretch denim” and a stretch knit are different amounts of stretchy. If you want to move freely all day, the knit will give you more.

Our jeans are not pure cotton, and here is why we say so

Real talk. Britannica says denim is typically pure cotton, though large quantities are made as cotton and synthetic blends. Ours are blends too. The men's sunfade gradient and vintage wash wide leg jeans are 68 percent cotton and 32 percent polyester. The women's vintage wash wide leg jeans are 80 percent cotton and 20 percent lyocell. The men's vintage wash barrel leg jeans are 74 percent polyester and 26 percent cotton. We list every percentage on the product page so you are never guessing, and you should hold any store that sells you “denim” to the same standard. If you want to understand what those blends do, our posts on Sorona vs polyester and the polyester alphabet cover the polyester side.

How to care for each one

For real denim, we will lean on the people who know it best. Levi's care guide for its own denim says to wash only about every ten wears and spot clean minor stains in between, to wash in cold water on a gentle cycle, turned inside out and zipped up, and to air dry inside out in the shade rather than machine dry, since machine drying may contribute to shrinking and fading. It also notes that new dark denim can shed extra dye, so wash it separately from light items the first time, and that raw denim is not pre-shrunk. That is one brand's advice for its own jeans, not a universal law, so check the tag on yours.

For faux denim, the right answer is the care label on the garment. Knit stretch leggings are not treated like raw selvedge jeans, and we are not going to give you rules we have not tested. Read the tag, wash it the way it says, and skip the heat if you can.

The water question: how much does a pair of jeans take?

You have probably seen a number for how much water a pair of jeans uses. Here is the one we could verify. In a 2015 life-cycle study published on its own site, Levi Strauss & Co. reported nearly 3,800 liters of water used over the life of a pair of jeans, which is about 1,000 gallons. It said growing the cotton was the biggest share at 68 percent, and that how the owner washes the jeans was the second-largest piece. Some quick math on that 68 percent works out to roughly 2,580 liters (about 680 gallons) for the cotton, though that is our arithmetic, not a figure the company printed.

Treat that number with the care it deserves. It is a single company's study from 2015, about its own jeans, and we could not check the method. It also says nothing about faux denim, so we are not going to claim our leggings are greener or worse. We do not have the data. What the study does suggest is that washing jeans less often matters, which lines up with the “wash every ten wears” advice above.

Denim myths, busted

• Myth: “Denim and jeans are the same word.” No. Denim is said to come from Nîmes and jeans from Genoa.
• Myth: “Levi Strauss invented jeans.” Not quite. He and Jacob Davis patented riveted pocket openings in 1873. The cloth and the pants already existed.
• Myth: “Jeggings are denim.” Only some. Knit jeggings are legging material made to look like denim. Denim jeggings are real denim with extra spandex.
• Myth: “The heavier the denim, the better.” Weight is a category, not a grade. A 12 oz and a 16 oz denim are built for different jobs.
• Myth: “Real denim is always 100 percent cotton.” Typically, yes. Always, no. Many are blends.
• Myth: “Faux means cheap and bad.” Faux just means it is a different fabric trying to look like another. A soft, stretchy knit that looks like jeans is doing exactly what it was built to do.

So which one should you wear?

• You want to be comfortable for hours: faux denim leggings. Stretchy, light and easy.
• You want the denim look under an oversized tee or a long top: faux denim. It reads as jeans, moves like leggings.
• You want pockets, structure and a classic jean feel: real denim.
• You want a pair that ages into something personal: real denim.
• You want a loose, baggy shape: real denim in a wide or barrel leg.
• You want to wear them the day they show up with zero break-in: faux denim.

Sources & further reading

• Wikipedia, Denim: warp-faced twill, indigo warp and white weft, fading, “serge de Nîmes,” stretch denim
• Britannica, Denim: twill construction, usually cotton, cotton-synthetic blends
• Wikipedia, Jeans: Genoa origin of the word, the 1873 patent
• Levi Strauss & Co., History: the 1873 patent and rivets
• Wikipedia, Jeggings: knit jeggings vs denim jeggings
• Heddels, denim weight guide: lightweight, mid-weight and heavyweight classes
• Levi's, How to wash and care for your denim: washing guidance
• Levi Strauss & Co., Life cycle assessment findings (March 17, 2015): water use over a pair of jeans