Explaining KPSI (knots per square inch) and the Different Types of Rug Knots Used in Weaving Carpets
What Are The Types of Knots Used To Weave A Rug?
In the world of carpet making, weavers use different types of rug knots. The type of knot used is largely based on region and culture, but this is not always the rule and you can find carpets that mimic other regions. This is especially true with more modern rugs where techniques became more uniform across regions. Before we explain the various knots you may find, let’s explain a few basics first.
First, you need to understand the terms warp and weft. The warp is the threads that run vertically on the carpet. They were tightly strung to the rug weaving loom as the carpet was being made. Sometimes, older texts will use the term “woof.” These tightly strung strings are the foundation of the carpet. They can be wool, cotton, silk, or sometimes exotic fibers. The type of warp used depends on region and what was available, affordable, or preferred by the rug weavers in local communities.
You will not see the warp threads of the carpet unless you look at the back. It is the weft that is the main attraction. The weft can either be woven in an over / under technique, tapestry woven (kilim), or consist of rows of knots. When knots are used, several rows of plain weave are used to keep them in place. Now, let’s explore the knots.
The most common type of knot is known as the Senneh, asymmetric knot, or Persian knot. It is used throughout the carpets of Iran, India, Central Asia, Pakistan, Afghanistan, and China. Each knot is worked over a pair of warp threads. The knot completely circles around one of the warp threads, but only passes behind the other. Both knot ends are visible on front side of the carpet and make up the design that you see.
The Ghiordes rug knot is also called the Turkish or symmetrical knot. It is used in that area that is now modern day Turkey, in rugs produced by the Kurdish tribes, and throughout the tribal rugs of the Caucasus Mountains. This knot completely encircles both pairs of warp threads, and makes an extremely strong and durable carpet, but it takes longer to weave than the Persian knot.
The Persian and Turkish knots are the most common ones, but sometimes, you will also find regional differences. One example is the Jufti knot that is used in Khorassan. This knot involves wrapping the threat around four, instead of two, strands of warp. These rugs have a lower number of knots per square inch and can be completed quickly. However, this knot does not allow as fine, intricate designs as the other knots and may have a cost in terms of structural integrity. The Jufti knot is sometimes used for large size rugs.
Another knot you may see on rare occasions is the Spanish rug knot, or single warp knot. This knot is created by tying the weft around a single warp thread. This is not seen as often today but was used in historical rugs and those from archaeological finds. Sometimes you will find a rug with diagonal or off set knotting, rather than having the knots lined up on the same warp threads.
The different types of rug knots explained:
The so-called knots that make up a pile rug are not actually knots, but loops, wrapped around pairs of adjacent warps. They may be wrapped in several configurations. In all cases they consist of the knot collar – the portion that literally wrap around the warps – and the ends that actually constitute the pile.
What are asymmetrical knots?
What are symmetrical knots?
Symmetrical knots are rug knots rgar have both ends of the yarn coming up together between two warps, with the knot collar wrapping around two warps. These knots also known as Ghiordes or Turkish rug knots.
What are jufti knots?
Jufti knots may be symmetrical or asymmetrical, but they utilize these configurations around pairs of warps rather than single warps, making the pile less dense and quicker to produce. Spanish knots are wrapped symmetrically around every other single warp in an actual knot, the only rug knot that truly merits the term.
Knots per Square Inch, or KPI in Rugs
What do the KPI, or Knots per Square Inch, in Carpets and Rugs really mean
Learning about the KPSI or Knots Per Square Inch – The density of the knots in a rug or fineness of a pile rug is measured by multiplying the vertical knot count by the horizontal knot count within a given area measurement, either square inches or square decimeters.
Anything up to around seventy to eighty knots per square inch is considered coarse. As the number approaches 100 or exceeds it, the count enters the medium range.
When a rug begins to approach about 200 knots per inch, the weave begins to be considered as fine. The finely woven area rugs may have as many as three or four hundred knots per inch, but such a count is considered to be exceptionally and even unusually fine.
To some extent the knot count depends on the size of the knots and the warps, i.e. the thickness and horizontal spacing of the yarns. But it also reflects how tightly the rows of knots and wefts are compacted vertically.