Posted on July 13, 2020 by Behnam Rugs

Exposed Knot-Heads and Threadbare Rugs: Causes and Prevention

You may have noticed white spots on your rug and wonder what they are and how to fix them. These white spots are known as knot-heads. All rugs have knot-heads, but they are hidden within the pile.

Traffic, wear, and vacuuming with the beater brush can bring knot-heads to the surface where they are visible at a glance. Although knot-heads are a natural occurrence that often happens as rugs age, they can affect the value of the rug as well as its overall “look.”

There are a few options to think about when it comes to fixing rugs with exposed knot-heads. You can cut away the knot-heads, you can color the white knot-heads to match the color of the rug, or you can reweave the portions of the rug that are suffering from exposed knot-heads after trimming them to prevent the threadbare look.

The height of the pile can affect the visibility of knot-heads. The density of the weave can also affect knot-head visibility.

When you imagine the body of your rug, think of it as a 3-dimensional object composed of three parts: the warp, the weft, and the pile.

The warp is composed of the yarn running the length of the rug. Knots are tied to the warp and thus it must be strong enough to hold tension throughout the weaving process. Sometimes a warp thread will break during the weaving process. When this happens, the weaver goes in and extends the broken warp thread and ties it off twice to connect the broken warp thread.

The weft is composed of the yarn running horizontally across the rug. The yarn is woven over and under the warp by the weft strings. The knots are combed down during the construction process to ensure a tight weave.

The pile is the raised surface of the rug that extends from the knots attached to the warp and weft. Pile length can be affected by knot density.

A rug can be composed by as few as 25 and as many as 1,000 knots per square inch (KPSI) or more. The lower the KPSI, the more obvious exposed knot-heads are. The pile of a rug may be long, short, thick, or thin. The visibility of knot-heads varies due to these factors.

For example, rugs with shorter piles are stronger than rugs with long piles. Low pile rugs show wear more evenly as well.

The country of origin, quality controls, materials (some are weaker and more prone to breakage), and workmanship can all affect the quality and strength of the knots.

As a rug ages, it loses pile due to wear, and eventually, knot-heads will begin to show through. In addition, sharp micro-dust accumulates in the base of the pile, aging the rug more quickly and leading to threadbare patches and exposed knot-heads.

This is just one reason why regular professional handwashing is so important for the health and longevity of your rugs. Removing the accumulated micro-dust is a vital part of rug maintenance and must be done by professionals with the proper equipment and knowledge.

Additionally, please note that wool rugs especially need regular professional cleaning, as the wool dries out over the years and loses its natural oils which protect the rug and prevent crushing and cutting due to micro-dust.

Rugs made of cotton or that have a cotton foundation are most likely to show visible white knot-heads after professional washing.

At Behnam Rugs, we offer a variety of solutions for exposed knot-heads. If your rug has only a few exposed knots, we will trim them as a complimentary part of your washing or repair job.

If the exposed knot-heads require more work, talk to us about color-matching the exposed white spots, as well as reweaving if the rug has a lot of knot-heads in need of trimming. Reweaving will restore some of the pile density.

As always, we are here to discuss any questions you may have about the care of your fine rugs. Call 972-733-0400 and we will answer all further questions you have about knot-heads after reading this article.