Why Do Towels Have That Weird Line?. A viral post on social media recently reignited an odd but surprisingly popular question: What’s that raised line across bath towels for? The internet offered everything from jokes (“face-to-butt separator”) to wild guesses like “racing stripes” — but the real answer is much more practical.

That line is called a dobby border, and it’s not just decorative. Textile experts explain it reinforces the towel’s edges, preventing fraying after repeated washes. It also keeps towels from getting bulky at the ends, helping them stay soft, absorbent, and easy to fold.

While it adds a clean, polished look, the dobby border’s real job is function: improving durability, maintaining shape, and offering a subtle space for design or branding.

So next time you dry off, give a little appreciation to that humble dobby border — it’s quietly doing more than you think.