You can’t just count the threads

The American obsession with super-sizing has moved into the bedroom, producing 20-inch mattresses and extra-deep sheets and pushing thread counts to new heights. One San Diego-based chain, Between the Sheets, now claims to stock the nation’s first 1,020-count sheets, offering the finest in “luxury, comfort, beauty and durability.”

But more isn’t always more.

“It’s not like horsepower,” says Filippo Arnaboldi, a director at Frette, the Italian linen house that has supplied Europe’s finest hotels as well as the Vatican.

Although a high thread count can make for a softer, stronger sheet, the quality of the fiber used is even more important. Weave and finish also contribute to how luxurious a sheet feels.

Thread count is simply the number of vertical and horizontal threads in 1 square inch of fabric. Anything above 200 used to be considered a luxury. Now department stores and Internet retailers routinely offer bedding with thread counts of 400 to 600. But the numbers can be deceptive -- many manufacturers use a form of “thread count inflation,” counting each double-ply strand of a thread twice.

“When you take that sheet home and wash it a few times, you realize you don’t have quite the nice sheet you thought you did,” says Patty Adair, a vice president with the American Textile Manufacturers Institute. “It should feel better and better the more you wash it.”

The majority of all sheets sold in the United States are made of polyester and cotton, a hardy blend designed to resist wrinkling. But the softest, most breathable sheets, textile experts say, are made from natural fibers -- cotton, silk, linen or any combination thereof.

Some of the world’s finest sheets, including some of those sold by Frette, feel sleek and soft with thread counts of just 200, because they are made of extra-long staple (or fiber) Egyptian cotton. Egyptian cotton is still regarded as the creme of the global crop, with the longest staple of any type of cotton -- 1 1/2 inches or greater -- which makes for the softest, strongest sheet, and less likely to pill or lint.

A close rival is pima cotton, named after the Pima Indians of the American Southwest, who helped raise it on experimental farms in Arizona in the early 1900s. Also grown in Peru and Australia, pima grown in the United States is usually referred to on packages by the trademarked term Supima.

Some bedding retailers and manufacturers say you could be better off choosing pima over Egyptian, since it describes a specific variety of premium cotton rather than a region where cotton is grown.

“Twenty-five years ago no one would have argued” that Egyptian cotton was the best, says Bob Hamilton, a vice president with Pillowtex, which owns the Fieldcrest brand. But these days, he says, Egypt is exporting other, lesser varieties of cotton in addition to the extra-long fiber it became known for.

The weave of a sheet also determines how it feels against your skin. This is largely a matter of taste, says Anne Fahey, who oversees buying for Strouds linen stores. “It’s like picking out a shirt,” she says. Do you prefer a silk shirt or one made from oxford cloth?

The crispest sheets are made from percale, a plain weave of 180 thread count and up, with equal numbers of vertical and horizontal threads. Satin or sateen sheets have a much silkier feel, which is achieved by running the vertical threads over not one, but four to eight horizontal threads. Light reflecting off the surface of the exposed threads creates a more lustrous fabric, but it is more likely to pill or tear than percale.

A twill weave falls somewhere in the middle, with vertical threads running over two or three horizontal threads in a diagonal rib (or “twill”). Sheets made from this weave have less shine than sateen, but are typically thicker and stronger than percale.

Lastly, there are the more complex weaves such as jacquard or damask, in which a special loom weaves a floral or geometric pattern into the fabric. These sheets typically have higher thread counts and a better drape, but they can also feel a little rougher because of the pattern’s texture.

The finish is perhaps the most overlooked and least understood part of a fine sheet. But good finishing is what distinguishes the 200- to 250-count percale sheets you slip into at fine hotels from other sheets, Fahey says.

Sheet companies typically use alkali, chemical or heat processes to smooth out sheets after they are woven, giving them a sheen and removing any stray fibers, and making them a bit more wrinkle resistant. Some companies offer “pure finish” sheets, which are given a final rinse to remove residual chemicals.

“Everyone is in a thread-count war, and thread count by itself doesn’t mean that much,” admits Paul Marx, who owns Between the Sheets with his wife, Sandra. Indeed, the record-breaking 1,020-count sheets the chain sells (for $1,299 per king set) are woven from four-ply threads.