There is a rumor that cold water can sometimes cause shrinkage. But we would argue that the exact opposite is true.
The reality is that when you wash items in hot water, especially items that have a lot of cotton in them, those items are much more likely to shrink.
Following up on a previous post about finding the softest t-shirt available and ranking the top 10 (click here to read about which ones rank the best), here is information about what happened when we washed those same items several times in cold water and in hot water.
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About testing for shrinkage*
We acknowledge that we can’t reasonably test every shirt out there. We had to narrow it down. So we wanted the test to be limited to shirts that had at least 25% cotton in the blend. So dri-fit moisture management type shirts were out. Sorry Nike and Under Armour, you’ll have to wait for a different type of test.
Additionally, we stuck to distributors that we know so that we could be sure to get the items in time.
This led us to 19 shirts from 10 different brands. The brands included American Apparel, Anvil, Bella + Canvas, District Made, District Threads, Gildan, Hanes, LAT, Next Level and Port & Company. We used all black shirts (or as dark as possible if the style didn’t have a pure black). And they were all size XL, in case you were curious about that.
The testing was pretty straightforward.
- First, we measured each shirt from neck to the bottom hem (length) and from armpit seam to armpit seam (width).
- Second, we washed them all in cold water and hung dry them.
- Third, we remeasured them in the same way and got our first set of results.
- Fourth, we washed them again, this time in hot water and dried them on a medium temperature.
- Fifth, we measured them again in the same way and got our second set of results.
Cold water washing
As you might expect, washing the shirts in cold water had little to no effect on the shirt's width or length. In fact, only 3 shirts were affected and those effects were tiny. So should you always wash in cold? We recommend it. It preserves the size and the printed image on your shirt better. And, according to this article in the Smithsonian, has other positive results as well. But in case you want to wash in hot...
The hot water effect
The shrinkage calculation was pretty simple. Remember geometry in school? Area = length time width to get the total square inches. We took the post hot wash area of the shirt and divided it by the pre-hot wash area of the shirt. That will tell you how much of the shirts area has shrunk. We turned it into a percentage and...shrinkage.
The Best of the Best
Here are the top 5 shirts that fared the best after a hot water wash and a medium dry.
#1 [0% shrinkage] Anvil 780 - 100% ring spun cotton (preshrunk)
#2 [1.92% shrinkage] Next Level N6210 - 60% cotton / 40% polyester
#3 [2.47% shrinkage] District Threads D142 - 50% polyester / 38% cotton / 12% rayon
#4 [2.93% shrinkage] Gildan 50/50 - 50% cotton / 50% polyester
#5 [3.50% shrinkage] Next Level 3600 - 100% ring spun cotton
The most shrinkage
These five came in at the bottom, showing the most shrinkage after a hot wash and medium dry.
#1 [8.23% shrinkage] LAT 6901 - 100% ring spun cotton
#2 [6.58% shrinkage] District Threads DT6000 - 100% ring spun cotton
#3 [5.53% shrinkage] District Made DM130 - 50% polyester / 25% cotton / 25% rayon
#4 [5.52% shrinkage] District Threads DT4000 - 100% ring spun cotton
#5 [5.33% shrinkage] Gildan 64000 - 100% ring spun cotton (preshrunk)
Surprises and Conclusions
For the most part, based on the previous years of experience with these brands and styles, the results seem consistent with what we have seen in the past. Really the only surprise was that the DM130, which is a tri-blend with minimum cotton, shrank as much as it did. What we did see and would be confident enough to say is that if you don't want your shirts to shrink, wash them in cold water. And, typically, the more cotton there is, the more likely it is to shrink when washed in hot water.
Obviously, when you only test one sample one time there is no way to draw absolute conclusions. Any scientist will tell you that your sample size needs to be much bigger to account for variability in the manufacturing. So take these results with a grain of salt.
You can see from the results that words like pre-shrunk can mean different things (compare the Anvil 780 and Gildan 64000 above) and even the country of manufacturing within a brand or style can make a huge difference (another case for why American Made builds consistency).
The next step would be performing the same style of testing on shirts using a much bigger sample size, controlling for variables such as country of manufacturing and doing more of an apples to apples comparison (all 100% ring spun).