The wool of sheep or hair of goat is undoubtedly more frequent among all raw materials of the rug due to its availability in the orient. Keeping sheep and goats has an ancient and spread record in oriental countries. Different races have been kept in various regions either cheap or expensive but with high quality. If we take a look at the wool of sheep under the microscope we can see a fiber with a wound surface and this feature makes spinning easy because individual fibers attach easily. These fibers are made of Creatine with a hole in the center, which gives flexibility to the fiber. Naturally, wool of sheep is composed of three different fibers: long wool, real wool, which is wound, and small and a firm part of dark wool. Invaluable wool, dark wool is under 5% and the amount of other fibers is more.

When long wool is more, we have persistent wool. Instead, when the percentage of real wool is more we have fine wool. The nature of wool depends on several elements: the race of sheep, weather, pastures, nourishing, age of sheep, the season of shearing, and the kind of sheep.

For instance, wool of a special type of sheep named Ovis Steatpyga, which is a ewe with a fatty tail in Persia. In general, wool attained from the back and shoulder of an animal is softer and longer than other parts and wool of lamb 8-14 months is more precious, wool sheared in spring is mass because it grew in the cold months of the year to protect the animal.