Tapering

Overlock and flat-felled seam types by highlighting the hem of a pair of jeans sewed with an overlocked inseam on the left and a flat-felled seam on the right.
This image explains the overlock and flat-felled seam types by highlighting the hem of a pair of jeans sewed with an overlocked inseam on the left and a flat-felled seam on the right.

Definition of inseam types: Overlock & flat-felled seams

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Jeans and pants are a part of our everyday lives, and there’s more to them than just the fabric. Have you ever thought about the seams? They play a big role in how your jeans and pants look, feel, and last.

Excluding tailored clothing which is generally a single lockstitch with merrow stitching or binding over the edges, the two main kinds of seams in jeans and similarly constructed pants are flat-felled and overlocked seams.

If you’re thinking about tailoring your jeans or pants (especially tapering) or just want to know more about fashion, it’s good to understand these seams. Why? Because each seam type comes with its own set of benefits and challenges that can significantly affect the alteration process, durability, and aesthetics.

Flat-felled vs. Overlocked seams

Flat-felled seams are the most common type of inseam construction on jeans and similarly constructed pants. They are created by folding the raw edges of the fabric over, and on themselves, then stitching them together. This creates a strong and durable seam that is also very flat and neat. These seams are celebrated for their durability, fray resistance, clean finish, and aesthetic value. Flat-felled seams are often used on high-quality jeans in the light-to-midweight fabric range but can be a problem with heavyweight or thick fabrics because of the multiple layers of folded fabrics required to sew through where seams meet and the fabric’s weight.

When it comes to sewing through multiple seams, manufacturers of heavyweight denim will use flat-felled seams at the seat, even though they must sew through 12 layers of fabric where the yoke and center seat seams meet, and avoid the flat-felled seam on the inseam, where 8 layers of fabric must be sewn through in the crotch, for several reasons.

First, in the seat area of jeans and similarly constructed pants, the flat-felled’s low profile, smoothness, and visual aesthetic have more value than an overlocked seam. Second, because of the shorter distance regarding sewing, errors can be more quickly corrected compared to the long distance at the inseam.

Some brands, such as Bravestar and a few others, will take on the massive challenge of producing heavyweight jeans with flat-felled inseams. Sewing flat-felled inseams of heavy jeans during tapering is tough in our experience, not because of the fabric’s thickness, but due to the weight and gravity pulling on the jeans while they hang under the off-the-arm sewing machine. The weight exerts a continual tug on the fabric, which the sewer is attempting to hold upward into the folder, which causes the fabric edges to turn over, to create flat-felled seams. Shorter sewing distances, such as the rear yoke and center seat seams, are not a problem. Longer sewing distances, such as the inseam, have three to four times the weight and force pulling the fabric down and out of the folder. As a result, every time the sewer adjusts their hand position while sewing, the fabric slips down, or lower in the folder, causing sewing problems. This is most certainly the most significant explanation for why factories prefer to produce heavyweight jeans with overlock inseams.

Overlock seams, also known as serged seams, are another common type of inseam construction. These are generally used on the insides of the garment. Overlock seams are created by an overlock machine, which stitches the seam, trims the seam allowance, and encases the edge of the fabric with thread, all in one step.

The overlocked seam is more valued at the inseam on heavyweight jeans because it’s easier to sew. Also, it does not create as much bulk where the seams meet in the crotch, where there is lots of movement, unlike the yoke area of the seat, which sits flat. Lastly, the more unsightly appearance of the overlock seam is not visible on the inseam unless the jeans are turned up at the hem.

While not as durable or aesthetically pleasing as flat-felled seams, overlock seams are quicker and more economical to produce. They also provide adequate fray resistance, which is particularly important on the raw edges of denim.

The Importance of seam type in Tapering Jeans and Pants

What does this have to do with getting your pants and jeans tapered? To begin with, the type of seam influences the method and difficulty of making an alteration. The vast majority of tailors will taper jeans and pants from the outseam to avoid the inseam because of a lack of equipment, knowledge, or both. This is not an option with selvedge clothing since it would damage the selvedge. Unless flared, or garments designed for curvy bodies, the shape of jeans and pants legs is typically drafted in the inseam, leaving the outseams mostly straight up to the hips. As a result, modifications should also be made to the inseam.

Tailoring flat-felled seams requires a feed-off-the-arm sewing machine to be done correctly, and in order to maintain the original construction. It also requires skill and knowledge of the construction techniques used on mass-produced read-to-wear garments, which often have very different rules than tailored clothing.

Overlock seams, on the other hand, are easier and faster to alter. An overlock machine, which is one of the more common types of sewing machines available in many types of tailoring establishments, can be used to cut and re-sew the seam. Most tailors will struggle with how to handle the top stitch that is sewn on top of overlocked seams. Without an off-the-arm machine, it’s impossible to sew a fresh top stitch from hem to hem in a single pass, without taking the garment apart. Because they can only sew so far up the leg, heading upward towards the crotch, they must either link a new top stitch to the previous one. Alternatively, they can open the outseams all the way to the hips in order to fit the jeans or pants through a flatbed machine, sewing around the inseam, in a single pass.

In Summary

Choosing to taper your jeans can give them a fresh lease of life, adapting them to changing trends or personal style preferences. But before you take them to a tailor, examine the inseam construction. Knowing whether you’re dealing with a flat-felled or overlocked seam will help you understand the complexity of the task and manage your expectations regarding cost, time, and final appearance. This way, you’ll ensure you’re making an informed decision about tailoring, helping your favorite denim remain a staple in your wardrobe for years to come.

The hem of tailored jeans next to parts of the original leg size shows an example of what it means to have "tapered jeans alterations."
This photo is an example of "tapered jeans alterations." It shows the hem of a pair of selvedge jeans that have been tapered from the inseam to narrow the leg opening. Next to the resized legs of the jeans is the original, wider portion of the jeans leg and discarded denim fabric, which has been cut away from the garment to decrease the leg size.

What are tapered jeans and pants?

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There are two meanings when it comes to “tapered” as related to jeans, pants, and other garments designed to wear over the legs.

  1. Related to alterations or tailoring: The term “tapered jeans” and “tapered pants” refer to garment bottoms worn over the legs that have been altered to narrow the shape of the legs.
  2. Related to the design or style of a garment: It’s a jean or pant with a leg that narrows dramatically from the knee to the leg opening. Tapered clothing should not be confused with slim-fit or other jeans and pants with legs that gradually decrease in size from the knee to the leg opening.

Example of use (related to alterations): I had my jeans tapered because the legs were too baggy.

Raw denim selvedge jeans that have been tapered using the tapering alterations process to narrow the leg shape. The excess denim from the jeans can be seen in front of the jeans.
Selvedge jeans that have been tapered using the tapering alterations process to narrow the leg shape while shortening the inseam length. The excess denim from the jeans can be seen in the front of the jeans.

Example of use (related to design or style): I bought tapered jeans because I wanted the leg opening to be small enough that the hem wouldn’t cover my shoes.

Lightwash tapered American-made jeans for women by Williamsburg Garment Company
Women’s boyfriend tapered fit jeans
Hope Street men's tapered American-made jeans
Men’s Hope Street tapered jeans
Cover image for TikTok video demonstrating how we expertly taper and take in the waist of jeans for the perfect fit.

Getting your fit right: Learn how we taper the leg while taking in the waist on jeans

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Do you want to know what sets us apart from the competition when it comes to denim alterations? In our latest TikTok video, you can see how we professionally taper the legs of a pair of jeans while also taking in the waist to make them fit just right.

@williamsburggar Denim heaven. The art of taking in the waist with tapering alterations on jeans. We perfect your fit. #denimyourway #denimhead #denimtailor #taperingjeans #jeanswaist #jeanswaistgap #selvedgedenim ♬ MAMBO OVER THE MOUNTAIN – Rick Hirsch

Make sure to follow us on TikTok to see more informative and entertaining videos. @williamsburggar

Outside view of selvedge jeans tapered from the inseam
Selvedge jeans tapered from the inseam

Tapering both flat-felled & overlock constructed jeans from the inseam explained

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It seems needless to say, selvedge jeans should always be tapered from the inseam. However, some people still take jeans to local tailors or dry cleaners, who are not equipped with proper denim sewing machines and expect them to properly taper their jeans.

Tapering jeans with double-needle chain stitched flat-felled seams

Butterflied open jeans on table show how to taper selvedge denim jeans from inseam
Photo of selvedge denim jeans with the flat-felled inseam opened and prepped for tapering from. the inseam.

This photo shows an example of tapering from the inseam in-process. These jeans were sewn with a double-needle chain stitched flat-felled (lap seam), so it has to be taken apart at the inseam. With the selvedge outseam shown at the center, the inseam is then trimmed to slim the leg down. Slimming is done from the hem, up to just above the knee, and eases out at the thigh.

A tailor without a feed-off-the-arm chain stitch sewing machine will never properly taper a pair of jeans with lap seam construction. Instead, they may use makeshift single needle sewing from the hem to the knee area. Leaving the area around the crotch and thigh with the original sewing, connecting the new sewing into the original.

Sewing a flat-felled seam on selvedge jeans with a Union Special 35800 feed-off-the-arm sewing machine
Union Special feed-off-the-arm sewing machine

For more detail on how we taper jeans constructed with a lap seam, watch our popular Youtube video.

How to taper jeans professionally

How to taper jeans with a single-needle overlocked inseam

Not all jeans have two needle chain stitch lap seam construction. Some have a single-needle topstitched inseam with overlock construction. We tapered the below Levi’s jeans, slimming the legs down and the excess fabric cut from them can be seen underneath.

Single-needle top stitched inseam Levi's selvedge jeans tapered from the inseam
Levi’s selvedge jeans tapered from the inseam.

Most tailors can handle overlocked jeans much easier than lap seams. Overlock sergers are machines commonly used by tailors. However, similar to how traditional tailors may handle lap seam sewing, they will likely remove the original topstitching to just above where the tapering will end. Then use the serger to sew the new leg shape. Finally, to reach high on the leg, so new topstitching can join with the original, the outseams are opened and subsequently closed after topstitching the inseam.

Process for tapering jeans with overlocked inseams as also seen in our TikTok video:

  1. Cut the inseam to the requested inseam length, plus 3/4″ to 1″ (depending on the hem height)
  2. Remove the single stitch on the inseam
  3. Press the inseam flat & draft the taper lines on each leg
  4. Trim & sew the new leg shape with a serger sewing machine
  5. Press the inseam to remove slack
  6. Sew a new single-needle chain stitch on the top of the inseam
  7. Chain stitch the hem 
@williamsburggar

This is how we taper jeans with a single-needle top stitched inseam. #selvedgedenim #samuraijeans #denimtailor

♬ original sound – Williamsburg Garment Co.

Depending on the details of the tapering, we first remove the entire original topstitching in order to sew a new unbroken/unjoined line. It doesn’t matter if the taper is to the knee, above the knee, or high into the thigh.

We taper jeans high into the thighs only when we get requests to make the thigh smaller. We always advise, that very little can be done at the thigh. Explaining, that the width of the thigh is in connection to the pattern’s shape. The seat, rise, and curve in the crotch (which affects movement) are all connected. Decreasing the thigh means the curve must be shortened and straightened, which will restrict movement. Taking from the curve also lowers the rise.

In other words, the best we suggest is easing the taper from the knee, high into the thigh, clipping a bit of the curve, thus reducing the thigh to a maximum close to 1/2 inch. We don’t feel comfortable taking much more.

Looking closely, the original overlock stitching can be seen in white thread and the new sewing in tan color. These jeans were tapered high, so we went completely around the crotch.

Overlocked hem of selvedge jeans with decreased leg opening
Inside details explain how to taper overlock selvedge jeans from inseam

As demonstrated in the TikTok video below, one of the biggest things that separate our work from tailors and denim specialists is our use of the Union Special feed-of-the-arm chain stitch machine. On single-needle overlock constructed jeans, it allows us to completely topstitch the inseam from hem to hem without opening the outseams.

@williamsburggar

Williamsburg Garment Company quickly explains how to professionally taper jeans. Setting us apart from common and amateur tailors, we take the pants apart, redraft the shape, then sew them back together following the original factory’s construction. #denimhead #selvedgedenim #denimtailor #taperingjeans

♬ original sound – Williamsburg Garment Co.

The Union Special is advantageous with selvedge jeans because you don’t want to disturb the outseams. Tailors who have to rely on tapering at the outseams will destroy the beauty of the selvedge jeans. The photo below is an example of what can happen when you give your jeans to a local tailor who doesn’t specialize in or understand denim. Luckily, he later did some research, found us and we saved his jeans.

Badly tailored selvedge jeans tapered from outseam
This is what can happen when you don’t know the difference between a tailor and a denim specialist.
Cover image for how to taper jeans video on TikTok
TikTok video "How we taper jeans from the inseam"

How to taper jeans Video on TikTok

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We are just getting started on TikTok creating cool, fun, and informative new videos. Take a look at this one which quickly takes you through the process of how to taper jeans to narrow the leg width on a pair of Samurai selvedge denim constructed with overlock sewing and a single-needle inseam.

Follow us on TikTok and Instagram @williamsburggar so you don’t miss new upcoming videos.

@williamsburggar

This is how we taper jeans with a single-needle top stitched inseam. #selvedgedenim #samuraijeans #denimtailor

♬ original sound – Williamsburg Garment Co.
Tapering jeans sewing on a Union Special 35800 feed-off-the-arm machinen

The Union Special, it’s like a plane, it flies itself!

After tapering a pair of jeans with an overlocked inseam, Isreal the production manager, and tapering expert at WGC shows off his sewing skills, single-needle topstitching the inseam just 1/8-inch from the seam edge with his eyes closed. To quote Isreal, working on the Union Special feed off the arm machine “It’s like a plane, it flies itself!”

*”Our Secret Trick for Sewing a Perfect Inseam – with Eyes Closed!” (Union Special 35800 Feed-Off-The-Arm)*

*WATCH-