Color in any Oriental carpet or Persian rug is perhaps its most important characteristic, coming to attention before any other aspect of these works of art. It is said among Oriental rug dealers that color is what sells a rug. Long ago, artisans in rug-producing countries learned to master chromatic mysteries lurking in the shrubs of their deserts, and the leaves of so many plants abundant in their surroundings. As a tree is known by its fruits, the dyer has place among his fellows by his hues. Each family of dyers has some peculiar and secret method of producing different shades. This subtle knowledge, however, has been carefully guarded against foreign participation.
Although silk is not the primary material used in the weaving of rugs, there are many pieces entirely made of pure silk where the number of knots per square inch is often very high due to the fact that silk is much thinner than wool and the silk knots tied on a silk foundation will be a lot smaller than wool knots. In many cases, silk is only used as “highlights” by skillful weavers making some flowers or parts of the design stand out. Just like wool, silk is a protein-based fiber and therefore more difficult to dye as opposed to cotton. First of all, silk has to get well saturated so it can absorb the dyestuff. The outer layer of silk fibers must be somehow cut open so the dye can reach the main body. There are sophisticated methods of achieving this task among professional dyers. Also, the temperature of the dyeing solution has to be maintained and never exceed a certain level in order to avoid shrinkage of the material. While stirring the solution occasionally, vinegar is added for extra luster and to promote level dyeing (even color). The solution needs to be kept at this temperature for a certain period of time, or else, the fabric will lose its shiny appearance very soon after the dyeing process is completed. Temperature has to be brought up to a full simmer while stirring the solution frequently. After the pot cools down completely, the fabric need to be laid flat to dry but not before it is given a thorough wash using mild detergents. Longer time, greater concentration of dyes, and higher temperatures are generally going to result in stronger colors.
Substantive dyes (known as direct dyes) get attached to the fiber without the help of another additive or chemical. Mordant dyes on the other hand, require a metal salt to prevent the color from washing out of the fiber. Even though the whole process of dyeing silk can be accomplished within a couple of hours, working with such a delicate fiber requires some experience. Different fibers absorb color very differently. Dyes do not come out the same color on silk fibers as they do on cotton, so it may take some experimentation to achieve the desired colors. Also for silk, mixed colors usually tend to shift one way or another. Maintenance of the temperature when dyeing silk is crucial as sudden changes in temperature can damage the fiber. Dyeing is indeed hard work, but rewards of creating wonderful shades are surely worth all this work.