Once upon a time, the only thing people counted in bed were sheep. Then one day, someone started counting coils. After that, counting became The Thing To Do, and it wasn’t long before people began to count the number of threads used to weave their sheets.

This story may be a slight exaggeration of how it played out. But all the same, when it comes to bedsheets, “thread count” has become a buzzword and a supposed metric for quality.

You’ve probably seen thread count advertised on every sheet set under the sun, but does anyone know what thread count really means?

For the scant few who don’t have the official definition at the tip of the tongue, here it is, courtesy of Cotton Inc.:

Thread count is the number of threads, both vertical (weft) and horizontal (warp), in a one-inch square of fabric.

Thread-count in bed sheets ranges from 80 to 1200. Most retailers sell sheets within the range of 180 to 500 thread-count.

Fun fact: no industry standards or legal regulations to measure the quality of bed sheets exist. Yet, quality standards for bedding are inextricably interwoven (no pun intended) with thread count.

Once thread count became a common quality assessment for sheets, the bedding industry seized the opportunity to fuel the fire, and performed something of a bait-and-switch, shifting the discussion away from quality to focus the attention on quantity.

Because the thinking goes that the more threads the better, it’s quite common for manufacturers to advertise a 300 thread count sheet as having a 600 thread count by using 2-ply thread (2 threads twisted together to weave a sheet).

Though manufacturers will tell you differently, it’s not thread count that matters; it’s staple length.

Staple length refers to the length of the cotton fiber. The longer the staple, the smoother and higher quality the cotton. Low quality, short-staple cotton often relies on chemical additives to make up for the poor quality of the fabric. Many manufacturers spray down cheap cotton with silicone to prevent the fibers from pilling.

It’s better to buy a 250 thread count sheet made from long staple cotton than a 600 thread count sheet made of cheap, low grade cotton.

A word to the wise: if you see a sheet with a thread count of 450 or above for less than $500, something’s wrong. As with everything else in life, there is no free lunch with bedsheets.