Why Do Shirts Twist After Washing? The Side-Seam Spiral, Explained

October 22, 2026 C.B. Shaw

Why do shirts twist after washing? Because the yarn inside the fabric was twisted when it was spun, and the knitting process locks that twist in like a coiled spring. Textile people call it torque or skew or spirality: the rows of loops in the fabric are no longer at right angles to each other, so the whole tube of fabric wants to rotate, and the side seams spiral around your body. Washing didn't create the problem. It released it. This post explains the science in plain English, how makers prevent it, and what you can realistically do.

If you've ever pulled a shirt out of the dryer and found the seam wandering across your stomach like a barber pole, you're in good company. And the answer is not that you washed it wrong. The shirt was a coiled spring in disguise the whole time. Washing just pulled the pin.

The spring in the yarn

Picture a rope. When you twist a rope tight, it wants to untwist. Yarn is the same: to hold fibers together, spinners twist them, and twisted yarn keeps a bit of “liveliness”, a tendency to spring back. A Cotton Incorporated technical bulletin (Knit Fabrics and the Reduction of Torque, copyright 2001) explains that Z-twist yarn (twisted one direction) gives right-hand skew, S-twist gives left-hand skew, and more twist means more liveliness and more skew.

The knitting machine adds its own opinion. T-shirt fabric is usually single jersey, knit on a circular machine that makes one big tube. The same bulletin says more yarn feeders on the machine give more course skew, that the rotation direction of the machine matters (it partly cancels or adds to the yarn's twist), and that a tighter stitch skews less. Three ingredients feed it: yarn twist, number of feeders and how the yarn is knitted.

Why washing makes it show up

Knits relax. When fabric comes off the machine it's under tension, and every trip through water, heat and tumbling lets it relax further and the stored-up twist is released. Cotton Incorporated found that knits skew as they relax off the machine, during wet processing and when dried without tension. The test method used to measure this, AATCC Test Method 179, specifically measures skew after five home wash and tumble-dry cycles, which tells you the industry knows fabrics that look straight in the store can twist after laundering. (We couldn't pin down the current edition year of that method, but the five-cycle idea is the point.) The twist was already in the fabric. Washing just reveals it.

How it's measured

The formula in Cotton Incorporated's bulletin is simple: mark a square on the fabric, launder it, then compare the two diagonals. Percent skew = 2 x (AC minus BD) divided by (AC plus BD), times 100. The international standard ISO 16322-3:2021 (published April 20, 2021, replacing a 2005 edition) measures spirality in garments after domestic laundering, not as manufactured.

What makes some shirts twist more than others

Factor	What sources say
Knit type	Single jersey is the worst. Interlock and rib knits mostly avoid it (a trade article, Fibre2Fashion, 2008).
Fiber blend	Cotton and polyester 50/50 skews less than 100 percent cotton (same trade article).
Spinning method	Friction-spun cotton shows the most spirality, then ring-spun (trade article). Cotton Incorporated found open-end rotor yarn skewed less than ring or air-jet. The two sources agree on rotor and disagree on air-jet, so the winner is still up for debate.
Drying	Drying without tension maximizes skew (Cotton Incorporated).

If you're curious how spinning and fiber choices affect everything else in a shirt, our posts on how to tell if a T-shirt is good quality and cotton vs polyester blends go further.

How makers fix it

Alternate S and Z yarn feeds on the machine, which greatly reduces skew (Cotton Incorporated).
Use balanced plied yarn. Z-and-Z plied yarn at 12.5 twists per inch gave 0.0 percent skew in their tests.
Cut the tube open and finish it flat. This straightens the vertical rows but shifts the distortion to the horizontal rows.
Fix it before finishing. Cotton Incorporated says that works better than straightening afterward.
Heat setting and mercerization reduce liveliness (a trade article).
Resin finishes were the best skew control in Cotton Incorporated's tests, but the trade article says resin isn't recommended for cotton because it weakens the yarn. The two sources fight about it, so resin doesn't get the crown.

Compacting helps less than resin, per Cotton Incorporated, and the trade article warns that straightening the vertical rows by hand can itself cause spirality. It's a hard problem. Even good makers fight it.

What can you do at home?

Honest answer: not a whole lot, and nobody has published a tested home trick. What the sources do point to:

Dry with tension and alignment. Because drying without tension maximizes skew, line-drying with the side seams lined up is the sensible move.
Choose differently next time. Rib or interlock knits and poly blends twist less.
Dampening and tugging the shirt back into shape may help a mild case. It's folk wisdom, so no promises.
Ironing it back falls in the same bucket: popular, untested.

A bit of history: how jersey got its name

The fabric most T-shirts are made of is called jersey, after the Channel Island. Wikipedia says it began as fishermen's underwear and sweaters, originally wool (a weaker source, and the claimed medieval roots didn't check out for us). The V&A museum adds a better-documented chapter: before Coco Chanel, jersey was cheap and practical, used mostly for men's underwear, sportswear and stockings. Chanel made her first garments from knitted jersey, and a belted silk jersey blouse from spring and summer 1916 is among the earliest surviving Chanel garments. In November 1916, British and American Vogue wrote that “Chanel is master of her art, and her art resides in jersey.” So the fabric in your tee was once underwear fabric, then high fashion, then everybody's favorite shirt. Not bad for a fisherman's undershirt. (The popular story linking the fabric to Lillie Langtry never held up in what we read, so we're skipping it.)

Twisting myths, graded

“Twisting means the shirt is cheap or defective.” Partly true. Quality matters, but even good single jersey can twist if the yarn wasn't balanced.
“Washing causes the twist.” Misleading. Washing reveals twist that was already in the yarn.
“Cotton always twists.” False. Interlock, rib and balanced-yarn single jersey twist little.
“Ironing or stretching fixes it permanently.” Unproven.
“The shirt is damaged.” Not exactly. The twist was in the yarn all along.

Questions people ask

Why do my T-shirts twist after washing?

Twisted yarn stores energy like a coiled spring, and the knit locks it in. Washing and drying let the fabric relax and release it, so the rows of loops skew and the seams spiral.

What is torque or spirality in knit fabric?

Names for the same thing: the rows of loops are angled away from 90 degrees, which makes a knit tube twist around itself.

Does a twisted shirt mean it's low quality?

Partly. Quality matters, but even decent single jersey can skew if it was never balanced.

Why does drying make it worse?

Cotton Incorporated says drying without tension maximizes skew, and the standard test measures skew after five wash and tumble-dry cycles.

Which knit twists the most?

Single jersey, per a trade article. Interlock and rib knits mostly avoid it.

Do cotton blends twist less?

A 50/50 cotton and polyester blend skews less than 100 percent cotton, according to a trade article.

How do manufacturers stop shirts from twisting?

By alternating yarn twist directions on the machine, using balanced plied yarn, and finishing the fabric carefully. Balanced plied yarn gave 0.0 percent skew in Cotton Incorporated's tests.

Can you fix a twisted shirt?

No tested home fix exists. Dampening and tugging it back may help a mild case, and ironing is the same story: popular, unproven.

How should I dry a shirt so it doesn't twist?

Line-dry it with the side seams aligned, since drying without tension maximizes skew.

Where does the word jersey come from?

From the Channel Island of Jersey, where the knit was reportedly made for fishermen. That origin comes from a weaker source.

How did Coco Chanel use jersey?

The V&A says she made her first garments from knitted jersey, and a silk jersey blouse from 1916 is among her earliest surviving pieces.