The warp refers to the vertical strands running up and down a rug. These are vital to the carpet's structure as the knots are tied. The wefts are also placed between them to keep the knots in place. The fringe of a rug is the tied loose ends of its warp.
The weft is used to keep the knots in place. Before and after each row of knots, the weft strand is passed through the warp and combed and beaten down; this compacts the row of knots, creating a tight structure.
PERSIAN RUG MATERIALS
Cotton is used for both warp and weft in most rugs. However, some tribal rugs use wool, and intricate silk rugs often use silk as a foundation and a pile.
Pile refers to the material or fiber used in weaving the rug. The primary materials used in Persian rugs are wool, silk, and cotton. Sometimes camel or goat wool is used by tribal weavers.
Wool is the most commonly used material in weaving handmade Persian rugs, mainly because it is soft and durable but also due to the availability of the natural resource to the people of Iran. Although camel or goats hair is sometimes used, in excess it is undesirable. While they may add sheen to a carpet they are very difficult to dye and the rug may lose its color faster than if woven with sheep wool. The best wool generally comes from colder high altitudes and the mountainous topography in parts of Iran is well suited to producing excellent quality. Other wool is imported from Australia and New Zealand who also produce excellent materials. Kork or Kurk wool is regarded as the best type of wool, this is high-quality wool which is extremely soft yet durable. The wool is shaven from only the shoulders and under-belly of a lamb on its virgin cut. This is when the wool is at its finest and is often used in conjunction with silk.
SUPER FINE WOOL
Salmas, Mako, Urmia, and Dasht-e Moghan regions in Azerbaijan; Torbat Heydariyeh, Neishabour, Quchan, Mashhad, and Sabzevar in Khorasan Razavi and North Khorasan, Bam, Jiroft, and Rafsanjan in Kerman province and Fars, Kurdistan, Kermanshah, Isfahan, Lorestan and Hamedan areas are the leading suppliers of "hand-woven carpet wool" Are. Makui and Moghani breeds in Makoo and Moghan Plain, Afshari and Kaboud Shirazi in Fars, and Qara Gol and Kurdi in Kurdistan are among the best sheep breeds in Iran. Torbat Heydariyeh wool is better in North Khorasan province than in other regions—and has long and twisted strands. Types of wool are divided into three categories in terms of diameter: First class wool, Second-grade wool' and Grade three wool. Grade 1 includes wool that is less than 30 microns. The second grade consists of wools 30 to 35 microns in diameter. Grade 3 wool includes wools that are 40 microns in diameter. In general, fleece in tropical parts of Iran is softer and more curly, and fleece in temperate and cold regions is coarser and less curly, which is more suitable for carpet weaving. Depending on the breed, New Zealand and Australian sheep raised for their wool are ideal for making finer yarns and are used in rugs with many ridges. Iranian wool gives a more authentic product with a better footprint due to its roughness, crease, and less curl. The best type of Iranian wool is obtained from Kermanshah, Khorasan, Khuzestan, and Baluch regions. Kermanshah and Khuzestan wools are suitable for coarsely woven carpets due to their high height and diameter, and Torbat Heydariyeh and Baluch wools are ideal for medium-woven rugs.
Natural silk is costly and therefore used less in rugs. From the cocoon of the silkworms, which thrive on mulberry leaves, silk originally came from China before being produced in other countries. Silk has the advantage over other natural fibers of being fine and extremely strong. If it were as thick as wool, there would be no contest in durability; however, as the intricate detail, work, and high expense go into making silk rugs, they are recommended to be used as wall hangings or in rooms with low traffic. Some rugs use small amounts of silk and an all-over wool pile to highlight details and add depth to the character. Under no circumstances should a whole silk rug be cleaned at home! If the carpet does need to be cleaned, it should be taken to a professional Persian rug specialist and dealt with on their recommendations.
Cotton is generally used in the foundation of rugs. However, some weavers (such as the Turkmen) use it to introduce white details, creating contrast in color and texture. In addition, mercerized cotton is sometimes used to create an "art-silk" appearance.
PERSIAN RUG DYES
The wool or silk is treated and dyed before the rug knotting process. There are conflicting views about rug dyes, with the more traditionalist believing only vegetable dyes should be used. The counter-argument is that chemical dyes have been used for over 100 years, and many shades and designs could not be achieved using only the natural dyeing process.
Both types of dye have their merits. Natural dyes often provide a more muted, and indeed natural, palette. In comparison, rugs using chrome dyes can be brighter, more vivid, and more lively than their plant and vegetable counterparts. It depends on the look you are trying to achieve.
Some chemical dyes are more color-fast than vegetable dyes, while some vegetable dyes are more color-fast than chrome dyes. But, again, it is a matter of opinion.
NATURAL & VEGETABLE DYES
Some of the most beautiful colors are obtained from natural dyes; not only do these colors appear more realistic, but their durability tends to be greater than chemical dyes.
Indigo, produced by the fermentation of indigo plant blossoms, is the source of all shades of blue. After around one week of fermentation, the solution becomes amber; when the wool is soaked in the solution and dried in the open air, it oxidizes, turning blue. Mixing different dyes creates various colors; for example, mixing saffron with indigo produces green. Saffron, pear leaves, almonds, and buckhorn berries have different shades of yellow. The most common dye made from plants is Madder, which creates a red color and is quite prevalent in older rugs. Black is obtained by submerging previously dyed brown wool in indigo or using dyes taken from the Logwood trees of Central America or the West Indies. Cochineal is a tiny insect. When the female is roasted and pulverized, the resulting powder produces hues of violet. Many colors in the purple range resulted in combining red and indigo.
The most commonly used vegetable dyes are indigo (initially obtained by extracting and fermenting the leaves of the indigo plant and used to dye wool blue), madder (produced by boiling the dried, chunked root of the madder plant in the dye pot to create a red color), and larkspur (made by boiling the crushed leaves, stems, and flowers of the larkspur plant). These dyes produce dark navy blue, rusty red, and muted gold. In addition, the expensive Saffron flower is used to create rare shades of yellow.
Long ago, dyers realized that as more wool was dyed in a single dye pot, colors became weaker and weaker. Dyers use this notion of depleted dyes to their advantage. The first dyeing produces a deep, intense color. Subsequent dyeing in the same dye pot has lighter, softer colors. Dyers also quickly learned to combine colors to create different hues. For instance, no "vegetable" dye material yields green, an actual color if you're interested in weaving a floral design. To create a green wool color, the wool is first dyed blue and then dyed again with yellow. If you look closely at the green color in a vegetable-dyed rug, you will commonly see that the color is uneven, blue-green in some areas, and yellow-green in others. It's because of the double-dyeing technique.
So, by using the notion that depleted dyes produce different hues and combining some paints through over-dyeing wool, dyers can produce a surprisingly large palette of colors from a minimal variety of materials.
In the late 19th century, people introduced aniline dyes to the Persian region, but early shades didn't work well for rug yarns. The colors were crude and faded quickly. So, at the start of the 20th century, the Persian government banned aniline dye imports. In addition, they created strict laws to burn down dye houses that produced aniline dyes and severely punished anyone who used illegally dyed yarn. These measures worked, and Persian weavers returned to using natural dyes until chrome dyes became available between WWI and WWII. Modern chrome dyes are reliable, colorfast, and come in various attractive colors and shades. Today, rug buyers can rest assured that the colors will only become more beautiful with age.
THE MEANING OF COLORS
Colors hold significant meaning in rug design across different cultures. For instance, green is considered sacred in Muslim countries as it represents 'Mohammed's coat,' while it is widely used in Chinese carpets. Conversely, yellow is seen as the Emperor's color in China. Red, on the other hand, is generally perceived as a symbol of power and wealth.
However, modern rug designs driven by commercial demand often overlook these cultural differences.
PERSIAN RUG DESIGN
A skilled artist designs the rug by hand before it is knotted. Detailed design plates or cartoons, which are life-sized paint-by-numbers, are used to create city rugs—these show which color of wool should be used for each knot. Tribal and village rugs may use this method for standard designs, but many are made from the weaver's imagination. Therefore, tribal rugs have more "errors" than city rugs. These imperfections indicate authenticity, and some collectors prefer the raw art form of tribal rugs to the more uniform appeal of city rugs.
Most Persian rugs are pile-woven, the knots tied by hand to the warp strings. Therefore, two factors are essential when discussing knots – density, and type.
Knot density refers to, and is measured by, the number of knots per square inch (KPSI). This is done by counting the number of knots in an inch down the warp and across the weft and multiplying these figures together.
Knot density could be a factor in the value of a rug, but this is not always true. Knot density is usually not a factor in nomadic and some village items. It is not a factor for collectors of these rugs because different standards than workshop rugs judge nomadic and village carpets. Nomads and village groups have various sophisticated tools than other city weaving groups. Their items are valued because their designs are created from memory, their dyes and materials are provided by nature, and most importantly, the weavers' way of life is expressed in them. These rugs generally have a 25 to 100 knots per square inch knot density. Rugs with higher knot density take longer to make, and since nomads migrate as the seasons change, they will have to carry the looms with them if their rugs still need to be finished in time for the migration. Therefore, their rugs tend to have a lower knot density than workshop rugs. The value of these rugs lies in their heritage and simplicity. They have artistic value.
However, in many cities and workshop rugs, knot density is vitally important to determine the price of a carpet. Similar to television resolutions, the more knots (or pixels) per square inch, the sharper the design (or picture). A skillful weaver can tie a knot in about ten seconds, meaning 6 knots per minute or 360 knots per hour. That means it would take a weaver around 6,480 hours to weave a 9x12-foot rug with a density of 150 knots per square inch. Divide this number by 8 (an 8-hour working day), and it would take one weaver 810 days (approximately two and a half years!) to weave such a rug. A rug as large as a 9x12 is usually woven by two or three weavers so that the above time can be reduced by half or a third, but the labor costs increase. This is one reason why most Persian rugs are considered prestigious items.
The different types or styles of knots have been culturally developed by the various groups and tribes of people as time progressed. The knotting process can be viewed in this video; different rug weaving areas use slightly different techniques and methods; however, the video shows the effort put into creating these masterpieces.
THE ASYMMETRICAL(PERSIAN OR SENNEH) KNOT
The asymmetrical knot is used in Iran and nearby countries such as India, Turkey, Egypt, and China. The yarn is wrapped around one warp strand to form this knot, passed under the neighboring strand, and returned to the surface. With this type of knot, a finer weave can be created.
THE SYMMETRICAL(TURKISH OR GHIORDE) KNOT
The symmetrical knot is used in Turkey, the Caucasus, and northern Iran. It is also used in some European rugs. To form this knot, the yarn is passed over two neighboring warp strands. Each end of the yarn is then wrapped behind one warp and brought back to the surface in the middle of the two warps.
THE JUFTI KNOT
The Jufti knot can be seen in the rugs of Khorasan, Iran. This knot can be either symmetrical or asymmetrical and is usually tied over four warps making the weaving process faster.
After the rug knotting is complete, the pile is very long and uneven, and the pattern is barely from the front side of the rug. At this stage, the pile must be carefully clipped and shaved to the correct height, showing the design and artwork and achieving the desired texture. Washing the rug ensures no color run later in life and removes excess dye and debris. This process may be repeated several times.
FINISHING & FRINGING
Finally, the rug is placed on a 'blocking' device to ensure no shrinkage has occurred during the wash; last-minute checks are made as quality control is vital. The rug is then packaged and flown or shipped to showrooms worldwide.
PERSIAN RUG TOOLS
The comb slides and beats down the weft between rows of knots. This comes, moved up and down the warp, pressing the knots in place, securing them before a new row is started.
A hook is a knife-like tool that becomes very narrow on the tip. This tool has two purposes - the weavers use the tip for separating the warp strands while tying a knot and then pulling out the yarn through the warp strands. The side of the hook, which works like a knife, is used for cutting the yarn after each knot is tied.
A rod used for spinning fiber into yarn.
Special scissors cut the long or uneven pile as the carpet is woven.
The knife is used to cut the threads after each knot is tied. This is sometimes done using the hook.
Design plates are used as a reference when creating the rug, showing the weaver what colors to use. Typically on grid paper, design plates are often drawn up by master weavers, famous designers, or artists. These are used to create some village rugs and all workshop rugs.
The loom is the frame that holds the rug together while weaving. Horizontal looms are the simplest type of loom. Nomads use them mainly because they can easily be dismantled during migration. Rugs woven on horizontal looms are generally small because they need to be finished in time for migration, and it is also challenging to weave large rugs on this kind of loom. Horizontal looms are constructed with four wooden bars similar to a frame. The distance between the two parallel sidebars depends on the width of the rug to be woven on the loom, and the distance between the top and the bottom bars determines the length of the carpet. The bars are secured to the ground by stakes or nails. After constructing the loom, the warp strands are attached to the top and bottom bars. The warp strands are usually very close to the ground. The weavers sit on the woven part to reach the unwoven top parts as the rug is woven, and rows of knots and wefts are added.
Vertical is specific to village and workshop rugs, and their assembly is more complicated than horizontal looms. A vertical loom consists of four bars, two sidebars from the ground up, and two horizontal bars--one at the bottom, close to the ground, and one at the top. This loom looks like a frame that is standing up. The warp strands are secured to the top and bottom bars. Rugs woven on vertical looms are more exact in dimensions and design. There are three types of vertical looms, although different versions of each style may exist: the Fixed Loom, the Tabriz or the Bunyan Loom, and the Roller Beam Loom.
On the Fixed Loom, the weaver sits on an adjustable seat in front of the loom. The center is raised as the rows of knots are added.
On the Tabriz or the Bunyan Loom, the warp strands are wrapped around and behind the top and bottom bars instead of being secured to them. On this loom, as the work progresses, the woven section of the rug is pulled down and behind the loom. This way, the weavers do not have to move. These looms are used in Iran in the Azerbaijan province, the cities of Arak, Qum, and Hamadan, and the commercial centers of Turkey.
ROLLER BEAM LOOM
On the Roller Beam Loom, the woven part of the rug is rolled around the lower beam. With this kind of loom, huge size rugs can be woven. This loom is the traditional loom used in villages of Turkey; it is also used in Iran and India. This loom is generally used for coarser weaves.
PARTS OF CARPET
It is the main backbone of a carpet, consisting of yarn strands stretching from top to bottom (height-wise, vertically). These strands are stretched on the loom before weaving begins. Once the rug is completed and cut from the loom, the ends of the warp make up the fringe. The warp is typically made of wool, cotton, or silk.
It is the collection of knots of yarn twisted between the warp strands. The knots are weaved in the Turkish (Traditional, Ghiordes, Symmetrical) knot or the Persian (Commercial, Senneh, Asymmetrical) knot. The Turkish knot is a double knot formed by looping the pile yarn across two warp strands and then drawing each end back through the inside of both warps. The Persian knot is a single knot formed by looping the pile yarn through two warp strands and then drawing it back through one. The Turkish knot is more difficult to tie and more durable than the Persian knot.
These are yarn strands inserted perpendicular (width-wise, horizontally) to the warp strands and woven in and out of the warp strands during weaving. It is typically made up of the same material as the warp but is only visible from the back of the rug. The number of weft strands that pass between the rows of knots is called shoots; sometimes, the weft strands are dyed.
Both edges of a woven rug are covered with overcast (a simple running stitch) or selvaged (finished with a woven band) to reinforce the edges, as they are particularly susceptible to wear.