Forget what you think you know about high thread count cotton bed sheets.

If you’re lucky, you’ll spend a full third of your life counting sheep and slumbering the night away on some luxurious, high thread count cotton sheets. What a lovely little daydream. Before you believe it, there are a few things you should know about high thread count cotton bed sheets.

Thread count, simply put, is the number of horizontal and vertical (warp and weft) threads contained in one square inch of fabric. For example, a 300 thread count sheet will contain 150 horizontal threads and an equal number of vertical threads.

As consumers, we’ve been taught to equate high thread count sheets with high quality. When you see thread count numbers in the high hundreds or even thousands, take a step back from this implausible product as there’s only so many threads that can fit in an inch.

Unscrupulous manufacturers exaggerate the thread count of their sheeting based on the yarn’s ply, not strands. Most likely that purportedly high thread count is the result of spinning short, low quality cotton, or worse, polyester filler fibers, into double, or triple ply yarns, ostensibly turning a 200 thread count sheet made with three-ply yarn into a 600 thread count sheet.

In general, if a sheet is marketed to contain over a 500 thread count, that is likely a fabrication. Even at high thread counts, low quality/high thread count cotton sheets are so densely woven they inhibit airflow around your body, making for a clammy night’s sleep. Moreover, sheets made from inferior cotton are far less durable and more susceptible to pilling, making for an uncomfortable night’s sleep, too.

So, how can you tell the good sheets from the not so good sheets?

The world’s finest sheets start with the best raw materials — and quality craftsmanship. Pima cotton and its premium counterpart, Supima, are grown exclusively in the arid desert states of the American southwest. What makes Supima cotton superior is its exceedingly soft, extra-long staple fibers. Today, Supima cotton products are synonymous with luxury.

Cristina and John Onciul are the owners of LateMornings (LateMornings.com), producers of luxury sheets and bedding. They explained that Egyptian cotton was once the benchmark for luxury cotton goods. Today, however, production has declined and such cotton is increasingly difficult to source, they said.

“We’ve found American-grown Supima cotton surpasses Egyptian cotton for quality — and durability,” said Cristina. “Thread count becomes less important as Supima’s long fibers can be woven into exceedingly dense, soft, and breathable fabrics. Additionally, Supima cotton sheets resist pilling, retain their color, and consistently outperform higher thread-count fabrics made from lesser quality cotton, and, they improve with use.”

A trademarked variety of cotton, you’ll see it listed by its full name “Supima cotton” – not just “cotton” on labels and product descriptions. If it doesn’t say “Supima,” it’s just cotton.

Another variable to consider when investing in high-quality cotton sheets is their weave. The most common weaves for bed sheets are percale and sateen, and each has distinct characteristics.

Percale, perhaps the most ubiquitous weave, is a simple one-over-and-one-under pattern that produces a tightly woven, crisp sheeting fabric that’s durable, breathable, and oh-so-soft on the skin. Exceedingly dense, yet lightweight, a percale weave is best for hotter climates, or for those who sleep on the warm side.

The next favorite is the sateen weave, which utilizes a unique three-over-one-under weave pattern that exposes more of the thread’s surface area, creating a sheeting fabric with a luminous luster, soft nap, and silky hand that improves with each washing.

Specialty weaves like Damask employ centuries old techniques to create beautifully patterned sheets that introduce elegance and opulence to your bedroom.

But no matter the weave you choose, when you’re ready to slip between the sheets for a healthy, comfortable, and restful night’s sleep, look for bedding made from the highest quality, untreated cotton (or linen) in the 250 to 400 thread count range.

Rest easy, these are numbers you can believe.

Nighty-night.