So you’ve got this T-shirt. It’s your favorite one. You put it on every time you need to feel good about yourself. It gives you definition. It gives you purpose. It gives you the appearance of a slimmer waistline. In fact, not only can you never see yourself parting with it, you’re also super reluctant to wash it with the frequency you probably should. After all, the care instructions read, in ink as black as night — 100 percent cotton.
You can only shriek in response: 100 PERCENT COTTON??? WON’T THAT SHRINK THE MOMENT IT HITS THE WASH??? OR DRYER — WHO THE FUCK KNOWS??? EITHER WAY, WON’T THAT ROB IT OF ALL ITS DEFINITION, PURPOSE AND WAIST-SLIMMING POWERS???
Not so fast with the despair. Technically speaking at least, cotton doesn’t shrink. It’s mostly capitalism at play. Per Wayzata Home Laundry and Dry Cleaners, your 100-percent cotton T-shirt — a garment made of cotton fibers that consist of long molecular chains that are linked end-to-end by hydrogen ions — is stretched to capacity when you pluck it from the rack. This is how retailers save money on material. “When cotton fibers are spun into thread, which is then woven into fabric, those fibers and the molecular chains making them up are stretched, pulled and twisted,” explains Wayzata. “This stresses the hydrogen holding everything together.”
Translation: Your brand new, unwashed T-shirt is actually larger than the cotton fibers naturally want to be. And so, when you throw that shirt in the wash, you’re merely giving its cotton fibers a chance to go back to their normal size. Thus, don’t think of it so much as shrinkage but as your shirt’s molecules returning to their proper resting place.
From there — considering you have to wash your clothes more than once (hopefully) — the number of washes it takes to notice an appreciable decrease in size depends on a number of factors, “such as mechanical action, detergent, temperature, load size and how the fabric was made,” Chad Parks, an expert at Whirlpool’s Institute of Home Science, writes over email.
For those reasons, you have to think about fabric shrinkage in terms of the fiber type (cotton), textile type (knit, non-woven or woven) and manufacturing method (stretching or pre-shrinking). “All will play a factor in how much or how long it takes for the fiber/textile to ‘relax,’ which is what consumers view as shrinkage,” Parks explains.
According to OnlineClothingStudy.com, while fabrics like polyester don’t shrink at all, woven cotton can typically shrink between 2 to 7 percent. Interestingly, rayon can shrink anywhere between 5 to 10 percent. Hence the reason why it’s best to dry clean those shirts. As a ballpark figure, Parks says knitted fabrics reach their most relaxed state after five laundering cycles, but “woven fabrics need 10 laundering cycles to get fully relaxed.” Again, though, he emphasizes that the most shrinkage occurs during the first laundering cycle.
Now, if you think you can get around this by never washing your favorite T-shirt, think again. A light sweat is more than enough to kick-start the shrinking process, and your shirt is sure to feel smaller once you dry off.
In other words, it all comes out in the wash.