Those lines on many bath towels aren’t just decoration. They’re usually a woven design feature called a dobby border or decorative band.
Why towels have them
They help stabilize the towel’s weave. The denser woven band can reinforce the fabric near the edges and help keep it from losing its shape.
They provide a visual border. The pattern makes the towel look more finished and can distinguish the decorative edge from the main terry fabric.
They can reduce excessive stretching at the ends. The tighter weave behaves differently from the fluffy pile in the center.
They help with manufacturing and folding. A defined border gives the towel a clear edge and contributes to a consistent finished shape.
One thing people often get wrong
The lines aren’t primarily there to make the towel more absorbent or to tell you where to fold it. The towel’s absorbency mainly comes from its terry loops, which increase the surface area available to absorb water.
So that seemingly decorative strip is actually a combination of construction, durability, and aesthetics.
