Have you ever gone shopping for new bath towels and wondered why, despite the other differing design elements, they all have those lines or stripes toward the hemmed end?

Well, even if you haven’t, I bet you are now.

And after someone asked the question on Twitter/X, everyone over there just had to find the answer as well.

what is the purpose of this part of a towel? pic.twitter.com/q4UYACVMDP

— Nate (@natemcgrady) March 13, 2025

Some people went off the cuff, guessing the line separated the parts of the towel for the face and then the private parts, while others wondered if they somehow helped the towels dry faster.

pic.twitter.com/4OB2dkMlGx

— sierra catalina (@sierracatalina1) March 13, 2025

The people who guessed that it had something to do with strengthening the towel were at least partially correct.

The line is called the “dobby border,” and along with strengthening the towel, they also improve its absorbency and prevent fraying despite numerous washes.

The Towel Hub explains more.

“Absorbency is one of the most important qualities of a good towel, but achieving the perfect balance between thickness and performance can be challenging. The woven strip helps maintain an even structure, preventing the edges from becoming too bulky. This ensures that the towel remains soft, lightweight, and easy to handle, making it more efficient for drying both the body and surfaces.”

The website also says they are there are aesthetic reason for the woven strip, too.

“The woven strip at both ends of a towel serves multiple practical purposes, from preventing fraying to enhancing durability, improving absorbency, and adding an elegant finishing touch. This small but essential feature ensures that towels last longer, dry faster, and maintain a polished appearance, making them an excellent choice for both personal and commercial use.”

So, there you have it.

Consider yourself just a little bit smarter now.

If you think that’s impressive, check out this story about a “goldmine” of lithium that was found in the U.S. that could completely change the EV battery game.