The pile weave
This is the way most carpets are woven – a pile of ‘knots’. A skeleton with two sets of thread – the warp (vertical) and weft (horizontal) – makes up the foundation of the carpet with knots in between each layer of weft. The weft interlaces the warp, going over and under adjacent warp threads, alternating in each successive row. There is also an additional row of ‘knots’ – the colored thread that makes up the pattern of a carpet, piece by piece, similar to the pixels on a digital photo – the finer the thread, the higher the resolution is of the finished design.
The warp must be very resistant, especially to stretching – as the weaving process can take years to complete. Two or three strands of undyed natural yarn are plied together to form each line of warp. The yarn is painstakingly wrapped around the top and bottom beams of the loom until there is a working surface wide enough, that is evenly spaced out, and where tension is equally distributed. Once the warping starts, it must be continued until finished or there are likely to be inaccuracies in the final design. The distance between the strands of warp will determine how detailed the final carpet will appear.
The weft is usually made of the same material as the warp, except that it can be dyed and is more loosely spun. The type of yarn used and the way it is arranged is also a crucial factor in the detail of the carpet in the vertical direction. Each row of knots is followed by either one, two, or three ‘shoots’ of weft which help to maintain the position of the knots while keeping the warp evenly spaced.
The pile is usually made up of two or three loosely spun bulky strands of dyed yarn. Each color is placed individually, like the pixels of a digital photo, which form the entire carpet motif. Different regions have various knotting techniques, of which the asymmetrical (Persian knot) and symmetrical (Turkish knot) are the most common.
Antique and modern rugs from Turkey, Turkmenistan, and the Caucuses use this knot system as well as Persian carpet-makers of Turkish or Kurdish descent. This is why the knot was formerly known as the ‘Turkish’ or ‘Ghiordes’ knot. Today, European carpets also use the symmetrical knot as it is considered to be the easiest knot to work.
Also known as the ‘Persian’ or ‘Senneh’ knot, this system is found in Iran, India, Turkmenistan, Turkey, Egypt, and China. Carpets woven with asymmetrical knots are usually finer, have a more detailed design, and thanks to a tighter weave, the fabric is more hard-wearing.
Jufti knots are either symmetrical or asymmetrical knots that are more quickly done by tying the pile around more than two warp threads. This type of knot is seen as a shortcut. Four warp threads are usually used, which makes for faster weaving, but a coarser design and weaker fabric.
The Tibetan knot is used for most of our modern carpets. A gauge rod is used to tie the Tibetan knot. It is held in front of the warp while the yarn is passed under and over either two or three strands of warp. The yarn is then cut to form the knots.