5 Things to Know Before Buying Bedsheets

In our sheet ratings, you’ll find sets from Amazon Basics, Brooklinen, and L.L.Bean, among others. Below, we outline some of the key findings that came out of our lab—and how you can use them to help you shop.

1. Sheets Can Shrink Significantly
   Cotton sheets we tested shrank up to 6 percent, and some no longer fit on even the thinnest mattress—an 8-inch-tall foam model—after just 15 washes.
   
   Our testers noted that initially, all cotton sheets could fit the depth of the queen-size mattress as marked on their packaging (though not all packages carry such an indication). But after 25 wash cycles, only a few could fit a 14-inch mattress, and only the Matouk Sierra set could fit an 18-inch mattress (even though it shrank a fair amount). That’s something to keep in mind if you have a particularly thick pillow-top mattress.
   
   The sheet set that shrank the least in our tests was the L.L.Bean Pima Percale. But it didn’t fit an 18-inch mattress after a year’s worth of washings, which our testers attribute more to the design of the sheets than to shrinkage.
   
2. Materials Make a Big Difference
   The most common materials used for sheets—such as cotton, cotton blends, rayon, and polyester—have different properties.
   
   The polyester sheet we tested hardly shrank at all, and fit an 18-inch mattress after a year’s worth of washing—though some might find sweating on a polyester sheet to be uncomfortable because the material doesn’t absorb water.
   
   Cotton sheets, on the other hand, shrank less—but still, only the top sheets in our ratings could fit a 14-inch mattress after a year’s worth of washing.
   
   The sheets tested made of bamboo viscose were highly absorbent (so expect long drying times) and shrank by more than 15 percent after our fit test. One fitted bamboo sheet couldn’t even fit an 8-inch mattress after a mere 10 washes.
   
3.  Thread Count Does Not Indicate Performance
   One of our top-rated sheet sets, the Matouk Sierra, has a claimed thread count of 350. Compare that with the Macy’s Charter Club Supima Cotton Sheet, which has a claimed thread count of 550. It sits near the bottom of our ratings. The package claims that the sheets could fit up to an 18-inch-deep mattress, but in our testing, we found that the Charter Club didn’t fit even a 10-inch mattress after a year’s worth of washings.
   
4. Price Doesn’t Indicate Performance
   At about $300, the Cozy Earth Bamboo Sheet is one of the most expensive in our ratings, but it isn’t close to being the best. The sheets from Mellanni performed better than the Cozy Earth sheets during testing, and they cost a tenth of the price. Both of these sheets are made from the same material, but the difference in performance suggests a lot of variation in how sheets are manufactured.
   
5. The Feel of Cotton Remains Constant
   We handled sheets before and after washing for our sensory perception test. A panel of staffers compared each sheet set with three reference fabrics, then rated each set on a scale of soft, softer, and softest.
   
   Of the sheets we tested, our panelists didn’t notice a significant difference in softness before and after a year’s worth of wash cycles. That means that if you’re feeling a set of sheets in a store, you can expect them to feel the same even after laundering them for about a year.

To test how well a set of sheets will serve you, we assess fit, softness, and wrinkling. We also test for strength and shrinkage, because we believe that good sheets should last.

Fit is important because if a fitted sheet (no matter how soft) shrinks so much that you can’t get it over your mattress, all other attributes are moot. All the sheets in our tests could initially fit the queen-size mattress depth claimed on their packaging.

In our shrinkage tests, we wash fitted sheets according to the manufacturer’s directions 25 times—equivalent to about a year’s worth of washing if you launder your linens every two weeks. After each wash, our testers put the sheet on mattresses of different depths to see whether the corners and sides still fit and tuck underneath. 

We also compare sheets after each wash cycle with a set of references to determine how much they wrinkle. Wrinkled sheets don’t look as neat and crisp on a bed, and you may even feel wrinkles when you lie down.

Our engineers assess the strength of the fibers with a machine that clamps both ends of the sheet sample and pulls it with increasing force until it tears. In our tests, none were weak enough to be a concern under normal usage. 

To measure softness, a panel of sensory testers compares each sheet with a standard of fabric swatches covering a range of softness levels.