Carpet Material and Techniques
The carpet material and techniques used by Iranians have not been changed much since ancient times. Natural dyes are still used in many types of Persian carpets and the material used are wool, silk, kork and cotton.
The Raw Material
Needless to say, sheep wool is one of the basic elements in the carpet industry; it is usually used to weave the pile of a carpet. Many years ago some of the Hamedan and Baluch rugs were woven with camel wool.
Iranian sheep have thick wool and more than 60-70% of the wool is the hetro type species. Due to this fact, it is a very suitable material for carpets as the warp is thick, coarse and strong. The quality of wool obtained from sheep raised in mild and mountainous areas is much better than that from sheep that are pastured in humid and low-lying grazing land. Moreover, the quality of wool sheared from sheep in the spring is always better than that sheared in the autumn.
Sheep’s wool contains many external substances and these should be carefully separated before spinning. These substances consist of the fat in the wool (lanolin), the sweat and the urine. The dried wool also contains potassium and sodium salts, water and ointments applied to the body of the animal to heal its wounds. To remove these substances, it is necessary to completely wash the wool. Then the water is thoroughly wrung out and the wool is spread on a clean area to dry. This operation can be carried out manually or at wool-washing factories that are equipped with mechanical apparatus. After the drying process, the spun and skinned wool is dyed in the preferred colors at the special dyeing factories. The spinning can be accomplished either by hand or by machinery,
In the latter case, the large quantity of wool is uniformly spun and twisted. Hand-spun wool is mostly used in the villages and in the quarters of the tribal carpet weavers.
The term refers to the soft wool that grows close to the skin of sheep, goats and camels. A comb is used to extract this fine wool which clings to the teeth of the comb. It is one of the principal elements from which fine and fairly expensive rugs are made.
Cotton fiber has an important role in the carpet weaving industry and it has seen increased use for weaving the warp and weft of the carpet.
Moths are not attracted to cotton, if the warp and weft of carpets are made of cotton; they only damage the pile without causing any holes.
It is much easier to create a new layer of pile on the lattice of the warp and weft that has been left intact. Cotton fiber is not good for making the pile of a rug; instead due to its strength and inflexibility it is suitable for making the warp and weft.
Produced by the larva of a species of moth commonly called the silkworm, silk has been successfully cultivated in Iran. The finest silk for rug making traditionally comes from an area around the Caspian Sea. This region produces a type referred to as Rasht Silk, which is regarded as the best in the world.
Because of the high price of the raw material, the production of silk rugs has sharply decreased. Silk fibers can also be used to make the warp, weft and the pile of a carpet. When compared with wool fibers of equal diameter, they are much stronger. Generally speaking, of the 100% weight of the carpet nearly 16-20% is the warp, another 10-18% the weft and the balance, 50-70% is the weight of the pile of the carpet.
In the carpet industry, dyeing plays an extremely important role as without colors no design can be created. The dyer is a central figure, and often somewhat mysterious, since the secrets of dyeing are closely held and passed on from one generation to another. This mystique is today less pronounced in urban centers but the dyer is nevertheless a figure of considerable importance and prestige.
Persian dyers, over centuries, have created a wide range of colors by combining various basic colors. With the analysis of light in a crystal prism, seven colors like those in a rainbow, i.e., violet, indigo, blue, green, orange and red are formed. In this collection of colors, yellow, red and blue are called the principal colors while violet, green and orange are the complementary ones. With a combination of these colors in different proportions, an exciting world of colors is formed. For instance, various shades of green are obtained from a mixture of yellow and blue. Various kinds of orange colors are obtained from the combination of yellow and red. Thus a variety of colors can be obtained.
The colors can be basically divided into two broad categories: Natural dyes and artificial dyes.
Often referred to as vegetable dyes, though many of these were obtained from animal and mineral sources. Despite the introduction of good quality synthetic dyes, which are reasonably cheap and plentiful the master dyers in Iran prefer the use of natural dyes. Natural dyes produce a subtle beauty of tone that has never been equaled by use of even the finest synthetic dyes. The natural dyes come from roots, flowers, leaves, fruits and barks of plants, or from animal sources such as cochineal and or mineral sources such as red soils.
The natural dyes had the advantage of being found in abundance in the natural environment.
Red is obtained from the roots of the madder plant (Rubia tinctorum) and also from the crushed bodies of female insects of the coccus cacti genus. Yellow is made from the Reseda plant, vine leaves and pomegranate skins. Blue is derived from Indigo plants.
Iranians are reputed to have had a long history of developing these natural dyes that were fast and attractive. Plutorch, the famous historian, while describing the victories of Alexander of Macedonia talks of the purple coloured fabrics which were looted by his soldiers and writes:
“the fastness of the colors and the durability of the fabrics woven in Iran are due to the fact that they made use a mixture of honey and wax…”
About 120 different kind of coloured plants have been identified in Iran. From the leaves, bark, roots, flowers and fruits of this plant, various colors are obtained. Additionally some natural dyes are extracted from lichens and alga. These lichens grow in the damp soil near the sea, in forests and on the rocks. These are collected and then dried, before being used as dyes. With a combination of substances derived from these lichens and various mordants, different shades of colors like brown, yellow and orange are obtained.
In the dyeing terminology mordants are substances used to improve the absorption of colors by the outer surface of the wool and ensure fastness of the colors, when exposed to sunlight or water. The outer surface of the wool has a characteristic of being waterproof and thus resistance to color absorption. Use of special chemical substance considerably reduces and even eliminates this color resistance layer and improves the darkness and lightness of the dye. Therefore, as a first step, the wool is treated with mordants, before it is immersed in the dyeing tanks.
The Principal Sources of Natural Colors
In Iran it is popularly known as golrangh. The plant grows up to the height of one meter. Its leaves are thorny and shiny. The flowers of this plant are initially Saffron colour, which later turn red. The Iranian dyers use the petals to dye the silk fiber to a golden red.
The variety of this plant that grows in Iran called Rubia Peregrina. The plant is cultivated in areas of Azerbaijan, Mazandaran, Kerman and in some central parts of Iran. It produces natural red colors. The root of this plant grows a depth of two meters or so in sandy soil, from which one gets a better colour essence. The plant root has a substance named “Rabitric acid” composed of sugar and colour essence called Alizarin. To produce the red colour, the root is taken out in late autumn and dried in the sun or in special furnaces (60 Degree Centigrade). However, the best colour is obtained, if it is dried in the shade. In the dyeing process Iranian dyers generally use sour milk which contains lactic acid. By use of this process they obtain fast and shiny colour.
Cochineal (Ghermez Daneh)
The existence and use of this insect has been known for a long time for preparing natural red colors. The red substance which is a compound of “Carminic acid”, oozes out of the body of this insect. The insect developed on the shores of the Persian Gulf and Sea of Oman and in parts of Baluchistan. The various species of Cochineal live on the Oak and cactus trees and they increase with such rapidity that they cover all the branches.
It is cultivated in Ghaenat and Birjand area of Khorasan province of Iran. Highly valued for its taste and flavor it is used to improve the quality of food. On account of its world wide demand, the price had a phenomenal increase; therefore, it is no longer used as dye.
It is a thorny tree. Its bark is boiled and the sap obtained from it is transformed into powder or crystallized form. It is then used for dyeing natural black and grey colors. Exposure to sunlight does not affect the colors produced from logwood. Together with different mordants logwood produced light purple, violet, grey and black colors. For obtaining pure black colour, Iranian dyers use a mixture of a logwood and Esparak.
Originally the plant was found in India from where it had been taken to different parts of the world. Mankind has known the Indigo bush for a long time. It was cultivated to produce blue and green colors. In Iran it was cultivated in Khuzestan and in the Souther Regions. With the development of artificial Indigo, the cultivation of Indigo plant has been reduced. There are the several varieties of indigo plant but these all contain one or two colour substances. When the leaves of this plant are crush& a green substance oozes out and as soon as it gets in contact with air, the colors transferred to blue. Indigo is one of the best natural dyes. It resists washing as well as rubbing and the color stays solid and fast.
Dyer’s Weed (Esparak)
It is a biennale plant, which produces yellow colour. It grows wild and in abundance in Iran. Due to continuous exposure to light the dye from this p gives fast yellow colour for many years. This dye has been extensively used in Iran. Despite easy availability of chemical dyes, Reseda has not lost its place with the dyer Iran and continues to be extensively used. The Esparak plant is also cultivated. All parts of the plant contain coloring substances the root and upper sections of the bush especially the flower give the best colour.
From the rootstalk, ordinary turmeric is obtained. Is it m ostly used in cooking and grows in plenty in Iran. Turmeric, when used with different mordants in the dyeing process produces several varieties of brown, dark, grey, greenish yellow and orange.
Plants containing Tannin
It was first grown in Iran and is today found in various parts of the world. The skin of its fruit is used for dyeing and grey and dark colors are obtained. It is used more than other plants containing tannin. The quantity of Tannin substance in Pomegranate is up to 40%.
From the trunk, branches, bark of this tree are extracted large quantities of tannin substance which are used for medicinal, tannery and dyeing purposes. The tannin substances contained in the bark of the Oak-tree with different mordants produce yellow-orange and brown colors.
Walnut trees are found in abundance in areas of Iran having a moderate climate. The nutshell of this plant contains tannin 35-40%. With use of different mordants the tannin in the shell produces brown and dark colors.
It resembles a plum and is dried before it matures. It has around 45% of tannin. Apart from dyeing, it is also used for medicinal purposes. Two varieties of this plant are in existence. “Yellow Myrabolan”, from which yellow colors is obtained and “black Myrabolan”, from which black and green colors are obtained by use of different mordants.
Other colour plants
The leaves of mulberry, vine, henna and plane trees are commonly used for the development of natural dyes, white mulberry gives yellow; black mulberry and its fruit, violet; red and grayish colors are obtained with use of different mordants. The leaves of the vine when brought in contact with galvanized iron olive green and when treated with alkaline salts give almost orange. Light and dark green colors are produced from plane tree leaves. Wool when boiled with corn straw gives light beige; if boiled with onion skin, it becomes pink; and with henna leaves, it gives a jasper green color.
With the expansion of textile and carpet weaving industries, a need was felt for producing chemical dyes, which would be cheaper, readily available and could give a variety of colors.
These synthetic dyes were introduced in Persia and Anatolia in the later half of t he 19th century. The first dye discovered by Perkins, appeared in the market in 1856. Following this, in 1869, two German scientists Graebe and Liebermann, produced the compound of Alizarin (a coloring substance present in the root of madder plant). In 1897, artificial Indigo, was discovered by German chemist Bayer and offered commercially, in the market. These synthetic dyes proved unsuitable for carpet yarns as these produced crude colors that were given to rapid fading. The fading of some chemical dyes when in contact with light or water created an unfavorable impression and made some believe that all synthetic dyes react similarly when faced with these unfavorable elements. In reality except for Aniline colors other synthetic dyes when compared with the natural dyes, often show a stronger reaction to light and water.
In 1903 the Persian government enforced strict laws, prohibiting use of these dyes. These measures proved effective, and Persian weavers went back to using natural dyes until the more reliable chrome dyes appeared on the market around 1920. Over the period of the last 50 years or so, dyes there are of reliable color-fast and made in a wide range of colors and shades have appeared on the world market.
Assured of the permanence and fastness of these dyes, the Persian rug weavers are now using extensively these chrome-based dyes, along with the natural dyes.
Reference: “The Persian Carpet” by Javad Nassiri